Encoding method, decoding method, computer-readable recording medium, and transmission method

Abstract

A decoding method according to one aspect of the present disclosure comprises: obtaining information on a basic prediction mode; generating a basic prediction block on the basis of the information on the basic prediction mode; obtaining information on an additional prediction mode; generating an additional prediction block on the basis of the information on the additional prediction mode; and generating a final prediction block on the basis of a combination of the basic prediction block and the additional prediction block, wherein the additional prediction mode may include at least one of an intra prediction mode and an intra block copy (IBC) prediction mode, and the information on the additional prediction mode may include at least one of information indicating whether the intra prediction mode is applied to the generation of the additional prediction block and information indicating whether the IBC prediction mode is applied to the generation of the additional prediction block.

Description

Encoding method, decoding method, computer-readable recording medium and transmission method The present disclosure relates to a method for encoding / decoding image information, a computer-readable recording medium for storing image information, and a method for transmitting image information. Recently, the demand for high-resolution, high-quality images, such as HD (High Definition) images and UHD (Ultra High Definition) images, is increasing in various application fields, and accordingly, high-efficiency image compression technologies are being discussed. There are various technologies such as inter prediction technology that predicts pixel values ​​included in the current picture from pictures before or after the current picture, intra prediction technology that predicts pixel values ​​included in the current picture using pixel information within the current picture, and entropy coding technology that assigns short codes to values ​​with high frequency of appearance and long codes to values ​​with low frequency of appearance, and these video compression technologies can be used to effectively compress and transmit or store video data. Accordingly, a highly efficient image compression technology is required to effectively transmit, store, and play high-resolution, high-quality image information. The present disclosure provides a method and device for performing inter prediction based on a multi-prediction block mode. The present disclosure seeks to provide a method and apparatus for signaling / parsing information regarding a multi-prediction block mode. The present disclosure seeks to provide a method and apparatus for deriving information regarding a multi-prediction block mode. A decoding method according to one aspect of the present disclosure comprises: obtaining information about a basic prediction mode; generating a basic prediction block based on the information about the basic prediction mode; obtaining information about an additional prediction mode; generating an additional prediction block based on the information about the additional prediction mode; and generating a final prediction block based on a combination of the basic prediction block and the additional prediction block; wherein the additional prediction mode includes at least one of an intra prediction mode or an IBC (Intra Block Copy) prediction mode, and the information about the additional prediction mode may include at least one of information indicating whether the intra prediction mode is applied to generation of the additional prediction block or information indicating whether the IBC prediction mode is applied to generation of the additional prediction block. A decoding method according to one aspect of the present disclosure includes: deriving information about a prediction from a neighboring block based on a prediction mode for a current block being determined to be a merge mode; and generating a prediction block for the current block based on the information about the prediction derived from the neighboring block; wherein generating the prediction block for the current block may include applying the multi-prediction block mode to the current block based on the information about the prediction derived from the neighboring block including information about the multi-prediction block mode. An encoding method according to one aspect of the present disclosure includes generating information indicating whether a multi-prediction block mode is applied to a current block; generating information about a basic prediction mode used to generate a basic prediction block and information about an additional prediction mode used to generate an additional prediction block based on whether the multi-prediction block mode is applied; and encoding information indicating whether the multi-prediction block mode is applied, information about the basic prediction mode, and information about the additional prediction mode; wherein the additional prediction mode includes at least one of an intra-prediction mode or an IBC-prediction mode, and the information about the additional prediction mode may include at least one of information indicating whether the intra-prediction mode is applied to generation of the additional prediction block or information indicating whether the IBC-prediction mode is applied to generation of the additional prediction block. An encoding method according to one aspect of the present disclosure includes: generating a merge candidate list and information indicating that the merge mode is applied to the current block based on the prediction mode for the current block being determined to be the merge mode; selecting one candidate from among candidates included in the merge candidate list and generating information indicating the selected candidate; and encoding information indicating that the merge mode is applied and information indicating the selected candidate; wherein the selected candidate corresponds to a neighboring block to which the multi-prediction block mode is applied, and information regarding the multi-prediction block mode applied to the selected candidate can be derived as information regarding the prediction of the current block. According to one aspect of the present disclosure, a recording medium is a computer-readable recording medium storing a bitstream, wherein the bitstream includes: information indicating whether a multi-prediction block mode is applied to a current block; information regarding a basic prediction mode used to generate a basic prediction block; and information regarding an additional prediction mode used to generate an additional prediction block; wherein the additional prediction mode includes at least one of an intra-prediction mode or an IBC-prediction mode, and the information regarding the additional prediction mode may include information indicating whether the intra-prediction mode is applied to generation of the additional prediction block or information indicating whether the IBC-prediction mode is applied to generation of the additional prediction block. According to one aspect of the present disclosure, a recording medium is a computer-readable recording medium storing a bitstream, wherein the bitstream includes: information indicating that the merge mode is applied to a current block; information indicating one candidate selected from among candidates included in a merge candidate list; and information regarding prediction of the selected candidate; wherein the selected candidate corresponds to a surrounding block to which a multi-prediction block mode is applied, and information regarding the multi-prediction block mode applied to the selected candidate can be derived as information regarding prediction of the current block. A transmission method according to one aspect of the present disclosure is a method of transmitting image information, comprising: generating the image information including a bitstream, wherein the bitstream includes information indicating whether a multi-prediction block mode is applied to a current block, information regarding a basic prediction mode used to generate a basic prediction block, and information regarding an additional prediction mode used to generate an additional prediction block; and transmitting the image information including the bitstream, wherein the additional prediction mode includes at least one of an intra-prediction mode or an IBC-prediction mode, and the information regarding the additional prediction mode may include at least one of information indicating whether the intra-prediction mode is applied to generation of the additional prediction block or information indicating whether the IBC-prediction mode is applied to generation of the additional prediction block. A transmission method according to one aspect of the present disclosure is a method of transmitting image information, comprising: generating the image information including a bitstream, wherein the bitstream includes information indicating whether the merge mode is applied to a current block, information indicating one candidate selected from among candidates included in a merge candidate list, and information regarding prediction of the selected candidate; and transmitting the image information including the bitstream, wherein the selected candidate corresponds to a neighboring block to which a multi-prediction block mode is applied, and information regarding the multi-prediction block mode applied to the selected candidate can be derived as information regarding prediction of the current block. According to the present disclosure, a method and device for performing inter prediction based on a multi-prediction block mode can be provided. According to the present disclosure, a method and device for signaling / parsing information regarding a multi-prediction block mode can be provided. According to the present disclosure, a method and device for deriving information about a multi-prediction block mode can be provided. The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below. FIG. 1 illustrates a video / image coding system according to the present disclosure. FIG. 2 is a schematic block diagram of an encoding device to which an embodiment of the present disclosure can be applied and in which encoding of a video / image signal is performed. FIG. 3 is a schematic block diagram of a decoding device to which an embodiment of the present disclosure can be applied and in which decoding of a video / image signal is performed. FIG. 4 illustrates an example of a video / image decoding method to which an embodiment of the present disclosure can be applied. FIG. 5 illustrates an example of a video / image encoding method to which an embodiment of the present disclosure can be applied. Figure 6 shows the reference samples (R) defined in PDPC according to various prediction modes. x-1 , R -1,y , R -1,-1 ) is indicated. Figure 7 is a diagram showing an example of how intra sub-partitions are divided. Figure 8 is a schematic diagram illustrating a matrix-based intra prediction process. FIG. 9 and FIG. 10 illustrate examples of inter prediction-based video / image encoding methods to which embodiments of the present disclosure can be applied. FIG. 11 and FIG. 12 illustrate examples of inter prediction-based video / image decoding methods to which embodiments of the present disclosure can be applied. FIG. 13 exemplarily illustrates an inter prediction procedure to which an embodiment of the present disclosure can be applied. Figure 14 is a diagram showing examples of blocks used to construct a merge candidate list. Figure 15 is a diagram showing four movements that can be expressed in the affine movement model. Figure 16 is a diagram showing an example of a control point motion vector used in affine motion prediction. Figure 17 is an example showing the positions of candidates in the configured affine merge mode. Figure 18 is a drawing showing an example of surrounding blocks for the current block. Figure 19 illustrates GPM segments grouped at the same angle as an example. Figure 20 illustrates the upper left neighboring blocks used in deriving CIIP weights. Figure 21 illustrates available IPM candidates for GPM including inter and intra prediction. Figure 22 illustrates sub-blocks at CU / PU boundaries and sub-PUs in ATMVP mode. Figure 23 shows an extended CU region used in BDOF. FIG. 24 is a diagram illustrating an inter prediction method performed by a decoding device according to an embodiment of the present disclosure, and FIG. 25 is a diagram illustrating examples of prediction blocks used in a multi-prediction block mode according to an embodiment of the present disclosure. FIG. 26 is a flowchart illustrating an example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. FIG. 27 is a flowchart showing another example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. FIG. 28 is a flowchart showing another example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. FIG. 29 is a flowchart showing another example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. FIG. 30 is a flowchart showing another example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. FIG. 31 is a flowchart showing another example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. Figure 32 is a diagram showing an example of inheriting from a surrounding block to which a multi-prediction block mode is applied, excluding the MHP-intra mode. Figure 33 is a diagram showing an example in which the number of intra modes inherited from surrounding blocks to which the multi-prediction block mode is applied is limited to 1. FIG. 34 is a flowchart showing an example of a decoding method performed by a decoding device according to one embodiment, in which information on an MHP-intra mode is derived at a decoder stage. FIG. 35 is a flowchart showing another example of a decoding method performed by a decoding device according to one embodiment, in which information for an MHP-intra mode is derived at a decoder stage. Figure 36 is a diagram for explaining the error between adjacent samples of the current block and adjacent samples of the base prediction block. Figure 37 is a flowchart illustrating an example of an operation for signaling / parsing information regarding MHP-Intra mode. Figure 38 is a flowchart illustrating another example of an operation for signaling / parsing information regarding MHP-Intra mode. Figure 39 is a flowchart illustrating another example of the operation of signaling / parsing information regarding MHP-Intra mode. Figure 40 is a drawing showing an example of the locations of adjacent / non-adjacent blocks of the current block. Figure 41 is a flowchart illustrating an example of the operation of signaling / parsing information required to generate an MHP_IBC block. Figure 42 is a flowchart illustrating another example of the operation of signaling / parsing the information required to generate an MHP_IBC block. Figure 43 is a flowchart illustrating another example of the operation of signaling / parsing weight information for MHP-Intra mode. Figure 44 is a flowchart illustrating another example of the operation of signaling / parsing weight information for MHP-Intra mode. Figure 45 is a diagram showing an example of dividing a current block and applying different weights to each divided area when applying weights to an MHP-intra prediction block. FIG. 46 is a flowchart showing an example of a decoding method performed in MHP-intra mode in a decoding method according to one embodiment. FIG. 47 is a diagram showing an example of the locations of reference samples and samples within a base prediction block used to generate an MHP-intra prediction block. Figure 48 shows an example in which the location of a sample of a basic prediction block is changed to an area adjacent to the prediction block in order to compare activity between samples corresponding to the same location. Figure 49 shows an example in which a strong filter is applied to the current block. Figure 50 is a flowchart illustrating an example of the operation of signaling / parsing filtering information for MHP-Intra mode. Figure 51 is a flowchart illustrating another example of the operation of signaling / parsing filtering information for MHP-Intra mode. FIG. 52 is a diagram illustrating an example of a content streaming system to which an embodiment according to the present disclosure can be applied. The present disclosure may be modified in various ways and encompasses numerous embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present disclosure. Similar reference numerals have been used to designate similar components throughout the description of each drawing. While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" includes a combination of multiple related items described herein or any of multiple related items described herein. When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening. The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. The present disclosure relates to video / image coding. For example, the methods / embodiments disclosed in this specification can be applied to methods disclosed in the versatile video coding (VVC) standard. In addition, the methods / embodiments disclosed in this specification can be applied to methods disclosed in the essential video coding (EVC) standard, the AOMedia Video 1 (AV1) standard, the second generation of audio video coding standard (AVS2), or the next generation of video / image coding standards (e.g., H.267 or H.268). This specification presents various embodiments of video / image coding, and unless otherwise stated, the embodiments may be performed in combination with each other. In this specification, video may refer to a set of images over time. A picture generally refers to a unit representing one image at a specific time point, and a slice / tile is a unit that constitutes part of a picture in coding. A slice / tile may include one or more coding tree units (CTUs). A picture may be composed of one or more slices / tiles. A tile is a rectangular area consisting of multiple CTUs within a specific tile column and a specific tile row of a picture. A tile column is a rectangular area of ​​CTUs that has a height equal to the height of the picture and a width specified by the syntax requirements of the picture parameter set. A tile row is a rectangular area of ​​CTUs that has a height specified by the picture parameter set and a width equal to the width of the picture. CTUs within a tile are arranged consecutively according to the CTU raster scan, while tiles within a picture may be arranged consecutively according to the tile raster scan. A slice may contain an integer number of complete tiles or an integer number of contiguous complete CTU rows within a picture, which may be exclusively contained within a single NAL unit. Meanwhile, a picture may be divided into two or more subpictures. A subpicture may be a rectangular region of one or more slices within a picture. A pixel, or pel, can refer to the smallest unit that constitutes a picture (or image). Additionally, the term "sample" can be used as a counterpart to a pixel. A sample can generally represent a pixel or a pixel value, and can represent only the pixel / pixel value of the luminance component, or only the pixel / pixel value of the chrominance component. A unit may represent a basic unit of image processing. A unit may include at least one of a specific region of a picture and information related to the region. One unit may include one luma block and two chroma (e.g., cb, cr) blocks. In some cases, the term "unit" may be used interchangeably with terms such as "block" or "area." In general, an MxN block may include a set (or array) of samples (or sample array) or transform coefficients consisting of M columns and N rows. In this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this specification can be interpreted as “A and / or B.” For example, “A, B or C” in this specification can mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.” As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C." In this specification, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.” Additionally, in this specification, “at least one of A, B and C” can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.” Additionally, “at least one of A, B or C” or “at least one of A, B and / or C” can mean “at least one of A, B and C.” Additionally, parentheses used herein may mean "for example." Specifically, when "prediction (intra-prediction)" is indicated, "intra-prediction" may be suggested as an example of "prediction." In other words, "prediction" in this specification is not limited to "intra-prediction," and "intra-prediction" may be suggested as an example of "prediction." Furthermore, even when "prediction (i.e., intra-prediction)" is indicated, "intra-prediction" may be suggested as an example of "prediction." Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously. FIG. 1 illustrates a video / image coding system according to the present disclosure. Referring to FIG. 1, a video / image coding system may include a first device (source device) and a second device (receiving device). A source device can transmit encoded video / image information or data to a receiving device via a digital storage medium or a network in the form of a file or streaming. The source device may include a video source, an encoding device, and a transmitting device. The receiving device may include a receiving device, a decoding device, and a renderer. The encoding device may be referred to as a video / image encoding device, and the decoding device may be referred to as a video / image decoding device. The transmitter may be included in the encoding device. The receiver may be included in the decoding device. The renderer may include a display unit, and the display unit may be configured as a separate device or an external component. A video source may obtain video / images through a process of capturing, synthesizing, or generating video / images. The video source may include a video / image capture device and / or a video / image generation device. The video / image capture device may include one or more cameras, a video / image archive containing previously captured video / images, etc. The video / image generation device may include a computer, a tablet, a smartphone, etc., and may (electronically) generate video / images. For example, a virtual video / image may be generated through a computer, etc., in which case the video / image capture process may be replaced by a process of generating related data. An encoding device can encode input video / images. The encoding device can perform a series of procedures, such as prediction, transformation, and quantization, to improve compression and coding efficiency. The encoded data (encoded video / image information) can be output in the form of a bitstream. The transmission unit can transmit encoded video / image information or data output in the form of a bitstream to the receiving unit of a receiving device via a digital storage medium or network in the form of a file or streaming. The digital storage medium can include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD, etc. The transmission unit can include an element for generating a media file via a predetermined file format and an element for transmission via a broadcasting / communication network. The receiving unit can receive / extract the bitstream and transmit it to a decoding device. The decoding device can decode the video / image by performing a series of procedures such as inverse quantization, inverse transformation, and prediction corresponding to the operation of the encoding device. The renderer can render decoded video / images. The rendered video / images can be displayed through the display unit. FIG. 2 is a schematic block diagram of an encoding device to which an embodiment of the present disclosure can be applied and in which encoding of a video / image signal is performed. Referring to FIG. 2, the encoding device (200) may be configured to include an image partitioner (210), a prediction unit (predictor) 220, a residual processor (residual processor) 230, an entropy encoder (entropy encoder) 240, an adder (adder) 250, a filter (filter) 260, and a memory (memory) 270. The prediction unit (220) may include an inter prediction unit (221) and an intra prediction unit (222). The residual processor (230) may include a transformer (transformer) 232, a quantizer (quantizer) 233, a dequantizer (dequantizer) 234, and an inverse transformer (inverse transformer) 235. The residual processing unit (230) may further include a subtractor (231). The addition unit (250) may be called a reconstructor or a recontructed block generator. The image segmentation unit (210), the prediction unit (220), the residual processing unit (230), the entropy encoding unit (240), the addition unit (250), and the filtering unit (260) described above may be configured by one or more hardware components (e.g., an encoding device chipset or processor) according to an embodiment. In addition, the memory (270) may include a decoded picture buffer (DPB) and may be configured by a digital storage medium. The hardware component may further include the memory (270) as an internal / external component. The image segmentation unit (210) can segment an input image (or picture, frame) input to the encoding device (200) into one or more processing units (PUs). For example, the processing units may be called coding units (CUs). In this case, the coding units may be recursively segmented from a coding tree unit (CTU) or a largest coding unit (LCU) according to a QTBTTT (Quad-Tree Binary-Tree Ternary-Tree) structure. For example, a single coding unit may be split into multiple coding units with deeper depths based on a quad-tree structure, a binary tree structure, and / or a ternary structure. In this case, for example, the quad-tree structure may be applied first, and the binary tree structure and / or the ternary structure may be applied later. Alternatively, the binary tree structure may be applied before the quad-tree structure. The coding procedure according to the present specification may be performed based on the final coding unit that is no longer split. In this case, based on coding efficiency according to image characteristics, etc., the largest coding unit may be used directly as the final coding unit, or, if necessary, the coding unit may be recursively split into coding units of lower depths, and the coding unit with the optimal size may be used as the final coding unit. Here, the coding procedure may include procedures such as prediction, transformation, and restoration, which will be described later. As another example, the processing unit may further include a prediction unit (PU) or a transform unit (TU). In this case, the prediction unit and the transform unit may each be split or partitioned from the final coding unit described above. The prediction unit may be a unit of sample prediction, and the transform unit may be a unit for deriving a transform coefficient and / or a unit for deriving a residual signal from a transform coefficient. The term "unit" may be used interchangeably with terms such as "block" or "area" depending on the case. In general, an MxN block can represent a set of samples or transform coefficients consisting of M columns and N rows. A sample can generally represent a pixel or a pixel value, and can represent only a pixel / pixel value of a luminance component or only a pixel / pixel value of a chrominance component. A sample can be used as a term corresponding to a pixel or pel of a picture (or image). The encoding device (200) can generate a residual signal (residual block, residual sample array) by subtracting a prediction signal (prediction block, prediction sample array) output from an inter prediction unit (221) or an intra prediction unit (222) from an input video signal (original block, original sample array), and the generated residual signal is transmitted to a conversion unit (232). In this case, a unit that subtracts a prediction signal (prediction block, prediction sample array) from an input video signal (original block, original sample array) within the encoding device (200) may be called a subtraction unit (231). The prediction unit (220) can perform a prediction on a block to be processed (hereinafter, referred to as a current block) and generate a predicted block including prediction samples for the current block. The prediction unit (220) can determine whether intra prediction or inter prediction is applied on a current block or CU basis. The prediction unit (220) can generate various information related to prediction, such as prediction mode information, as described later in the description of each prediction mode, and transmit the information to the entropy encoding unit (240). The information related to prediction can be encoded by the entropy encoding unit (240) and output in the form of a bitstream. The intra prediction unit (222) can predict the current block by referring to samples within the current picture. The referenced samples, i.e., the reference samples, may be located in the neighborhood of the current block or may be located a certain distance away from the current block depending on the prediction mode. In intra prediction, the prediction modes may include one or more non-directional modes and multiple directional modes. The non-directional mode may include at least one of the DC mode or the planar mode. The directional mode may include 33 directional modes or 65 directional modes depending on the degree of detail in the prediction direction. However, this is merely an example, and a greater or lesser number of directional modes may be used depending on the settings. The intra prediction unit (222) may also determine the prediction mode applied to the current block by using the prediction mode applied to the neighboring blocks. The inter prediction unit (221) can derive a prediction block for the current block based on a reference block (reference sample array) specified by a motion vector on a reference picture. At this time, in order to reduce the amount of motion information transmitted in the inter prediction mode, the motion information can be predicted in units of blocks, sub-blocks, or samples based on the correlation of the motion information between the neighboring blocks and the current block. The motion information can include a motion vector and a reference picture index. The motion information can further include inter prediction direction information (L0 prediction, L1 prediction, Bi prediction, etc.). In the case of inter prediction, the neighboring block can include a spatial neighboring block existing in the current picture and a temporal neighboring block existing in the reference picture. The reference picture including the reference block and the reference picture including the temporal neighboring block may be the same or different. Temporal neighboring blocks may be called collocated reference blocks, collocated CUs (colCUs), etc., and reference pictures including temporal neighboring blocks may be called collocated pictures (colPic). For example, the inter prediction unit (221) may construct a motion information candidate list based on neighboring blocks, and generate information indicating which candidate is used to derive the motion vector and / or reference picture index of the current block. Inter prediction may be performed based on various prediction modes, and for example, in the case of skip mode and merge mode, the inter prediction unit (221) may use the motion information of neighboring blocks as the motion information of the current block. In the case of skip mode, unlike the merge mode, a residual signal may not be transmitted.In the motion vector prediction (MVP) mode, the motion vector of the surrounding blocks is used as a motion vector predictor, and the motion vector of the current block can be indicated by signaling the motion vector difference. The prediction unit (220) can generate a prediction signal based on various prediction methods described below. For example, the prediction unit can apply intra prediction or inter prediction for prediction of a single block, and can also apply intra prediction and inter prediction simultaneously. This can be called combined inter and intra prediction (CIIP) mode. In addition, the prediction unit can be based on an intra block copy (IBC) prediction mode or a palette mode for prediction of a block. The IBC prediction mode or palette mode can be used for content image / video coding such as games, such as screen content coding (SCC). IBC basically performs prediction within the current picture, but can be performed similarly to inter prediction in that it derives a reference block within the current picture. That is, IBC can utilize at least one of the inter prediction techniques described herein. Palette mode can be viewed as an example of intra coding or intra prediction. When the palette mode is applied, sample values ​​within a picture can be signaled based on information about the palette table and palette index. The prediction signal generated through the prediction unit (220) can be used to generate a restoration signal or a residual signal. The transform unit (232) can apply a transform technique to the residual signal to generate transform coefficients. For example, the transform technique can include at least one of a Discrete Cosine Transform (DCT), a Discrete Sine Transform (DST), a Karhunen-Loeve Transform (KLT), a Graph-Based Transform (GBT), or a Conditionally Non-linear Transform (CNT). Here, GBT refers to a transform obtained from a graph when the relationship information between pixels is expressed as a graph. CNT refers to a transform obtained based on generating a prediction signal using all previously restored pixels. In addition, the transform process can be applied to a pixel block having a square size and the same size, or can be applied to a block of a non-square variable size. The quantization unit (233) quantizes the transform coefficients and transmits them to the entropy encoding unit (240), and the entropy encoding unit (240) can encode the quantized signal (information about the quantized transform coefficients) and output it as a bitstream. The information about the quantized transform coefficients can be called residual information. The quantization unit (233) can rearrange the quantized transform coefficients in a block form into a one-dimensional vector form based on the coefficient scan order, and can also generate information about the quantized transform coefficients based on the quantized transform coefficients in the one-dimensional vector form. The entropy encoding unit (240) can perform various encoding methods such as exponential Golomb, context-adaptive variable length coding (CAVLC), context-adaptive binary arithmetic coding (CABAC), etc. The entropy encoding unit (240) can also encode information necessary for video / image restoration (e.g., values ​​of syntax elements, etc.) together or separately from quantized transform coefficients. Encoded information (e.g., encoded video / image information) can be transmitted or stored in the form of a bitstream in units of NAL (network abstraction layer) units. The video / image information may further include information on various parameter sets, such as an adaptation parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). In addition, the video / image information may further include general constraint information. In the present specification, information and / or syntax elements transmitted / signaled from an encoding device to a decoding device may be included in the video / image information. The video / image information may be encoded through the above-described encoding procedure and included in the bitstream. The bitstream may be transmitted via a network or stored in a digital storage medium. Here, the network may include a broadcasting network and / or a communication network, and the digital storage medium may include various storage media, such as a USB, SD, CD, DVD, Blu-ray, HDD, or SSD. The signal output from the entropy encoding unit (240) may be configured as an internal / external element of the encoding device (200) by a transmitting unit (not shown) and / or a storing unit (not shown), or the transmitting unit may be included in the entropy encoding unit (240). The quantized transform coefficients output from the quantization unit (233) can be used to generate a prediction signal. For example, by applying inverse quantization and inverse transformation to the quantized transform coefficients through the inverse quantization unit (234) and the inverse transform unit (235), a residual signal (residual block or residual samples) can be reconstructed. The addition unit (250) can generate a reconstructed signal (reconstructed picture, reconstructed block, reconstructed sample array) by adding the reconstructed residual signal to the prediction signal output from the inter prediction unit (221) or the intra prediction unit (222). When there is no residual for the block to be processed, such as when skip mode is applied, the predicted block can be used as a reconstructed block. The addition unit (250) may be called a reconstructor or a reconstructed block generation unit. The generated restoration signal can be used for intra prediction of the next processing target block within the current picture, and can also be used for inter prediction of the next picture after filtering as described below. Meanwhile, LMCS (luma mapping with chroma scaling) may be applied during the picture encoding and / or restoration process. The filtering unit (260) can improve subjective / objective picture quality by applying filtering to the restoration signal. For example, the filtering unit (260) can apply various filtering methods to the restoration picture to generate a modified restoration picture, and store the modified restoration picture in the memory (270), specifically, in the DPB of the memory (270). The various filtering methods can include deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, etc. The filtering unit (260) can generate various information regarding filtering and transmit it to the entropy encoding unit (240). The information regarding filtering can be encoded by the entropy encoding unit (240) and output in the form of a bitstream. The modified restored picture transmitted to the memory (270) can be used as a reference picture in the inter prediction unit (221). Through this, when inter prediction is applied, the encoding device can avoid prediction mismatch between the encoding device (200) and the decoding device, and can also improve encoding efficiency. The DPB of the memory (270) can store the modified restored picture to be used as a reference picture in the inter prediction unit (221). The memory (270) can store motion information of a block from which motion information in the current picture is derived (or encoded) and / or motion information of blocks in a picture that has already been restored. The stored motion information can be transferred to the inter prediction unit (221) to be used as motion information of a spatial neighboring block or motion information of a temporal neighboring block. The memory (270) can store restored samples of restored blocks in the current picture and transfer them to the intra prediction unit (222). Image information output in the form of a bitstream from the encoding device (200) can be transmitted to the decoding device (300). FIG. 3 is a schematic block diagram of a decoding device to which an embodiment of the present disclosure can be applied and in which decoding of a video / image signal is performed. Image information transmitted in the form of a bitstream from the encoding device (200) can be received by the decoding device (300). Referring to FIG. 3, the decoding device (300) may be configured to include an entropy decoder (310), a residual processor (320), a predictor (330), an adder (340), a filter (350), and a memory (360). The predictor (330) may include an inter-prediction unit (332) and an intra-prediction unit (331). The residual processor (320) may include a dequantizer (321) and an inverse transformer (321). The entropy decoding unit (310), residual processing unit (320), prediction unit (330), addition unit (340), and filtering unit (350) described above may be configured by a single hardware component (e.g., a decoding device chipset or processor) depending on the embodiment. In addition, the memory (360) may include a decoded picture buffer (DPB) and may be configured by a digital storage medium. The hardware component may further include the memory (360) as an internal / external component. When a bitstream including video / image information is input, the decoding device (300) can restore the image corresponding to the process in which the video / image information is processed in the encoding device of FIG. 2. For example, the decoding device (300) can derive units / blocks based on block division-related information obtained from the bitstream. The decoding device (300) can perform decoding using a processing unit applied in the encoding device. Accordingly, the processing unit of decoding may be a coding unit, and the coding unit may be divided from a coding tree unit or a maximum coding unit according to a quad tree structure, a binary tree structure, and / or a ternary tree structure. One or more transform units may be derived from the coding unit. Then, the restored image signal decoded and output through the decoding device (300) can be reproduced through a reproduction device. The decoding device (300) can receive a signal output from the encoding device of FIG. 2 in the form of a bitstream, and the received signal can be decoded through the entropy decoding unit (310). For example, the entropy decoding unit (310) can parse the bitstream to derive information (e.g., video / image information) necessary for image restoration (or picture restoration). The video / image information may further include information on various parameter sets, such as an adaptation parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS). In addition, the video / image information may further include general constraint information. The decoding device can decode the picture further based on the information on the parameter set and / or the general constraint information. The signaling / received information and / or syntax elements described later in this specification can be decoded and obtained from the bitstream through the decoding procedure. For example, the entropy decoding unit (310) can decode information in a bitstream based on a coding method such as exponential Golomb coding, CAVLC, or CABAC, and output the values ​​of syntax elements required for image restoration and the quantized values ​​of transform coefficients for residuals. More specifically, the CABAC entropy decoding method receives a bin corresponding to each syntax element in the bitstream, determines a context model using information of the syntax element to be decoded and decoding information of the surrounding and decoding target blocks or information of symbols / bins decoded in the previous step, and predicts the occurrence probability of the bin according to the determined context model to perform arithmetic decoding of the bin to generate a symbol corresponding to the value of each syntax element.At this time, the CABAC entropy decoding method can update the context model using the information of the decoded symbol / bin for the context model of the next symbol / bin after determining the context model. Information regarding prediction among the information decoded by the entropy decoding unit (310) is provided to the prediction unit (inter prediction unit (332) and intra prediction unit (331)), and residual values ​​on which entropy decoding is performed by the entropy decoding unit (310), i.e., quantized transform coefficients and related parameter information, can be input to the residual processing unit (320). The residual processing unit (320) can derive a residual signal (residual block, residual samples, residual sample array). In addition, information regarding filtering among the information decoded by the entropy decoding unit (310) can be provided to the filtering unit (350). Meanwhile, a receiving unit (not shown) that receives a signal output from an encoding device may be further configured as an internal / external element of a decoding device (300), or the receiving unit may be a component of an entropy decoding unit (310). Meanwhile, a decoding device according to the present specification may be called a video / video / picture decoding device, and the decoding device may be divided into an information decoding device (video / video / picture information decoding device) and a sample decoding device (video / video / picture sample decoding device). The information decoding device may include the entropy decoding unit (310), and the sample decoding device may include at least one of the inverse quantization unit (321), the inverse transformation unit (322), the addition unit (340), the filtering unit (350), the memory (360), the inter prediction unit (332), and the intra prediction unit (331). The inverse quantization unit (321) can inverse quantize the quantized transform coefficients and output the transform coefficients. The inverse quantization unit (321) can rearrange the quantized transform coefficients into a two-dimensional block form. In this case, the rearrangement can be performed based on the coefficient scanning order performed in the encoding device. The inverse quantization unit (321) can perform inverse quantization on the quantized transform coefficients using quantization parameters (e.g., quantization step size information) and obtain transform coefficients. In the inverse transform unit (322), the transform coefficients are inversely transformed to obtain a residual signal (residual block, residual sample array). The prediction unit (320) can perform a prediction on the current block and generate a predicted block including prediction samples for the current block. The prediction unit (320) can determine whether intra-prediction or inter-prediction is applied to the current block based on the information regarding the prediction output from the entropy decoding unit (310), and can determine a specific intra / inter-prediction mode. The prediction unit (320) can generate a prediction signal based on various prediction methods described below. For example, the prediction unit (320) can apply intra prediction or inter prediction for prediction of a single block, and can also apply intra prediction and inter prediction simultaneously. This can be called combined inter and intra prediction (CIIP) mode. In addition, the prediction unit can be based on an intra block copy (IBC) prediction mode or a palette mode for prediction of a block. The IBC prediction mode or palette mode can be used for content image / video coding such as games, such as screen content coding (SCC). IBC basically performs prediction within the current picture, but can be performed similarly to inter prediction in that it derives a reference block within the current picture. That is, IBC can utilize at least one of the inter prediction techniques described herein. The palette mode can be viewed as an example of intra coding or intra prediction. When palette mode is applied, information about the palette table and palette index may be signaled and included in the video / image information. The intra prediction unit (331) can predict the current block by referring to samples within the current picture. The referenced samples may be located in the neighborhood of the current block, or may be located a certain distance away from the current block, depending on the prediction mode. In intra prediction, the prediction modes may include one or more non-directional modes and multiple directional modes. The intra prediction unit (331) may also determine the prediction mode applied to the current block by using the prediction mode applied to the neighboring blocks. The inter prediction unit (332) can derive a prediction block for the current block based on a reference block (reference sample array) specified by a motion vector on a reference picture. At this time, in order to reduce the amount of motion information transmitted in the inter prediction mode, the motion information can be predicted in units of blocks, sub-blocks, or samples based on the correlation of the motion information between the neighboring blocks and the current block. The motion information can include a motion vector and a reference picture index. The motion information can further include inter prediction direction information (L0 prediction, L1 prediction, Bi prediction, etc.). In the case of inter prediction, the neighboring blocks can include spatial neighboring blocks existing in the current picture and temporal neighboring blocks existing in the reference picture. For example, the inter prediction unit (332) can construct a motion information candidate list based on the neighboring blocks, and derive the motion vector and / or reference picture index of the current block based on the received candidate selection information. Inter prediction can be performed based on various prediction modes, and information about the prediction can include information indicating an inter prediction mode for the current block. The addition unit (340) can generate a restoration signal (restored picture, restoration block, restoration sample array) by adding the acquired residual signal to the prediction signal (prediction block, prediction sample array) output from the prediction unit (including the inter-prediction unit (332) and / or intra-prediction unit (331)). When there is no residual for the block to be processed, such as when skip mode is applied, the prediction block can be used as the restoration block. The addition unit (340) may be referred to as a restoration unit or restoration block generation unit. The generated restoration signal may be used for intra prediction of the next processing target block within the current picture, may be output after filtering as described below, or may be used for inter prediction of the next picture. Meanwhile, LMCS (luma mapping with chroma scaling) may be applied during the picture decoding process. The filtering unit (350) can improve subjective / objective image quality by applying filtering to the restored signal. For example, the filtering unit (350) can apply various filtering methods to the restored picture to generate a modified restored picture, and transmit the modified restored picture to the memory (360), specifically, to the DPB of the memory (360). The various filtering methods can include deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, etc. The (modified) reconstructed picture stored in the DPB of the memory (360) can be used as a reference picture in the inter prediction unit (332). The memory (360) can store motion information of a block from which motion information in the current picture is derived (or decoded) and / or motion information of blocks in an already reconstructed picture. The stored motion information can be transmitted to the inter prediction unit (332) to be used as motion information of a spatial neighboring block or motion information of a temporal neighboring block. The memory (360) can store reconstructed samples of reconstructed blocks in the current picture and transmit them to the intra prediction unit (331). In this specification, the embodiments described in the filtering unit (260), the inter prediction unit (221), and the intra prediction unit (222) of the encoding device (200) can be applied to the filtering unit (350), the inter prediction unit (332), and the intra prediction unit (331) of the decoding device (300) in the same or corresponding manner, respectively. FIG. 4 illustrates an example of a video / image decoding method to which an embodiment of the present disclosure can be applied. In image / video coding, the pictures that make up an image / video can be encoded / decoded according to a series of decoding orders. The picture order corresponding to the output order of the decoded pictures can be set differently from the decoding order, and based on this, not only forward prediction but also backward prediction can be performed during inter prediction. In FIG. 4, S400 may be performed in the entropy decoding unit (310) of the aforementioned decoding device (300), S410 may be performed in the prediction unit (330), S420 may be performed in the residual processing unit (320), S430 may be performed in the addition unit (340), and S440 may be performed in the filtering unit (350). S400 may include a decoding procedure according to the present disclosure, S410 may include an inter / intra prediction procedure according to the present disclosure, S420 may include a residual processing procedure according to the present disclosure, S430 may include a block / picture restoration procedure according to the present disclosure, and S440 may include an in-loop filtering procedure according to the present disclosure. Referring to FIG. 4, the decoding device obtains image / video information from a bitstream (S400), performs prediction based on the obtained image / video information (S410), and restores a picture through residual processing (S420, inverse quantization for quantized transform coefficients, inverse transformation) (S430). A modified restored picture can be generated by applying an in-loop filtering procedure (S440) to a restored picture generated through the above restoration procedure, and the modified restored picture can be output as a decoded picture and can be stored in a buffer or memory of a decoding device to be used as a reference picture in an inter prediction procedure when decoding a next picture. In some cases, the in-loop filtering procedure can be omitted, in which case the restored picture can be output as a decoded picture and can be stored in a buffer or memory of a decoding device to be used as a reference picture in an inter prediction procedure when decoding a next picture. The in-loop filtering procedure (S440) may include a deblocking filtering procedure, a sample adaptive offset (SAO) procedure, an adaptive loop filter (ALF) procedure, and / or a bi-lateral filter procedure, and some or all of them may be omitted. In addition, one or some of the deblocking filtering procedure, the sample adaptive offset (SAO) procedure, the adaptive loop filter (ALF) procedure, and the bi-lateral filter procedure may be sequentially applied, or all of them may be sequentially applied. For example, the SAO procedure may be performed after the deblocking filtering procedure is applied to the restored picture. Or, for example, the ALF procedure may be performed after the deblocking filtering procedure is applied to the restored picture. This may also be performed in an encoding device. FIG. 5 illustrates an example of a video / image encoding method to which an embodiment of the present disclosure can be applied. In FIG. 5, the prediction step (S500) may be performed in the prediction unit (220) of the encoding device (200) described above, residual processing (S510) based on the prediction result may be performed in the residual processing unit (230), and the step (S520) of encoding image information including prediction information and residual information may be performed in the entropy encoding unit (240). S500 may include an inter / intra prediction procedure according to the present disclosure, S510 may include a residual processing procedure according to the present disclosure, and S520 may include an encoding procedure according to the present disclosure. The encoding procedure may optionally include a procedure for encoding information for picture restoration (e.g., prediction information, residual information, partitioning information, etc.) and outputting it in the form of a bitstream, as well as a procedure for generating a restored picture for the current picture and a procedure for applying in-loop filtering to the restored picture. The encoding device (200) can derive (corrected) residual samples from the quantized transform coefficients through the inverse quantization unit (234) and the inverse transformation unit (235), and can generate a restored picture based on the prediction samples and (corrected) residual samples, which are outputs of S500. The restored picture generated in this way can be the same as the restored picture generated by the decoding device (300) described above. A modified restored picture can be generated through an in-loop filtering procedure for the restored picture, which can be stored in a buffer or memory, and, as in the case of the decoding device, can be used as a reference picture in the inter prediction procedure when encoding a subsequent picture. As described above, some or all of the in-loop filtering procedure may be omitted in some cases. When the in-loop filtering procedure is performed, (in-loop) filtering-related information (parameters) may be encoded by the entropy encoding unit (240) and output in the form of a bitstream, and the decoding device (300) may perform the in-loop filtering procedure in the same manner as the encoding device based on the filtering-related information. Through this in-loop filtering procedure, noise occurring during image / video coding, such as blocking artifacts and ringing artifacts, can be reduced, and subjective / objective image quality can be improved. In addition, by performing the in-loop filtering procedure in both the encoding device (200) and the decoding device (300), the same prediction results can be derived from the encoding device (200) and the decoding device (300), thereby increasing the reliability of picture coding and reducing the amount of data that must be transmitted for picture coding. As described above, the picture restoration procedure can be performed not only in the decoding device (300) but also in the encoding device (200). A restoration block can be generated based on intra-prediction / inter-prediction for each block, and a restoration picture including the restoration blocks can be generated. If the current picture / slice / tile group is an I picture / slice / tile group, the blocks included in the current picture / slice / tile group can be restored based only on intra-prediction. On the other hand, if the current picture / slice / tile group is a P or B picture / slice / tile group, the blocks included in the current picture / slice / tile group can be restored based on intra-prediction or inter-prediction. In this case, inter-prediction may be applied to some blocks in the current picture / slice / tile group, and intra-prediction may be applied to some remaining blocks. The color component of a picture may include a luma component and a chroma component, and unless explicitly limited in the present disclosure, embodiments according to the present disclosure may be applied to the luma component and the chroma component. Intra prediction The prediction unit (220, 330) of the encoding device (200) / decoding device (300) can derive a reference sample according to the intra prediction mode of the current block among the surrounding samples of the current block, and can generate a prediction sample of the current block based on the reference sample. For example, (i) the prediction sample can be derived based on the average or interpolation of neighboring reference samples of the current block, and (ii) the prediction sample can be derived based on a reference sample existing in a specific (prediction) direction with respect to the prediction sample among the neighboring reference samples of the current block. The case of (i) can be called a non-directional mode or a non-angular mode, and the case of (ii) can be called a directional mode or an angular mode. Additionally, linear interpolation intra prediction (LIP) may be applied to perform intra prediction on the current block by linearly interpolating prediction sample values ​​generated based on the intra prediction mode of the current block. Additionally, a temporary prediction sample of the current block may be derived based on filtered peripheral reference samples, and a prediction sample of the current block may be derived by weighting at least one reference sample derived according to an intra prediction mode among existing peripheral reference samples, i.e., unfiltered peripheral reference samples, and the temporary prediction sample. Such prediction may be referred to as Position Dependent Intra Prediction Combination (PDPC). In addition, intra prediction encoding can be performed by selecting a reference sample line with the highest prediction accuracy among the surrounding multiple reference sample lines of the current block, deriving a prediction sample using the reference sample located in the prediction direction of the selected line, and then instructing (signaling) the used reference sample line to the decoding device. This case can be referred to as multi-reference line intra prediction (MRL) or MRL-based intra prediction. Additionally, the current block can be divided into vertical or horizontal subpartitions, and intra prediction can be performed based on the same intra prediction mode, while peripheral reference samples can be derived and utilized for each subpartition. In other words, in this case, the intra prediction mode for the current block is applied equally to the subpartitions, but peripheral reference samples can be derived and utilized for each subpartition, thereby improving intra prediction performance in some cases. This prediction method can be called intra subpartitions (IPS) or IPS-based intra prediction. In addition, if the prediction direction based on the prediction sample points between surrounding reference samples, that is, if the prediction direction points to a fractional sample location, the value of the prediction sample can also be derived through interpolation of multiple reference samples located around the prediction direction (around the fractional sample location). The intra prediction methods described above may be referred to as intra prediction types, as distinguished from intra prediction modes. Intra prediction types may be referred to by various terms, such as intra prediction techniques, intra prediction tools, intra prediction detailed modes, or supplementary intra prediction modes. For example, an intra prediction type (or supplementary intra prediction mode, etc.) may include at least one of the above-described LIP, PDPC, MRL, and ISP. Information about the intra prediction type may be encoded by an encoding device and transmitted to a decoding device as part of a bitstream. Information about the intra prediction type may be implemented and transmitted in various forms, such as flag information indicating whether each intra prediction type is applied or index information indicating one of multiple intra prediction types. The MPM list for deriving the intra prediction mode described above may be configured differently depending on the intra prediction type. Alternatively, the MPM list may be configured in common regardless of the intra prediction type. PDPC (Position Dependent intra Prediction Combination) prediction According to PDPC, filtering can be performed based on a predefined filter to derive filtered reference samples, and a temporary prediction sample of the current block can be derived based on the intra prediction mode of the current block and the filtered reference samples. The prediction sample of the current block can be derived by weighting at least one reference sample derived according to the intra prediction mode among existing reference samples, i.e., unfiltered reference samples, and the temporary prediction sample. Here, the predefined filter can be one of five 7-tap filters. Alternatively, the predefined filter can be one of a 3-tap filter, a 5-tap filter, and a 7-tap filter. The 3-tap filter, the 5-tap filter, and the 7-tap filter can represent a filter having 3 filter coefficients, a filter having 5 filter coefficients, and a filter having 7 filter coefficients, respectively. For example, the prediction results of the intra planner mode can be further modified by PDPC. Alternatively, as an example, PDPC can be applied to an intra planar mode, an intra DC mode, a horizontal intra prediction mode, a vertical intra prediction mode, a bottom-left intra prediction mode (i.e., a 2-time intra prediction mode), eight directional intra prediction modes adjacent to a bottom-left intra prediction mode, a top-right intra prediction mode, and eight directional intra prediction modes adjacent to a top-right intra prediction mode without separate signaling. Specifically, when PDPC is applied, the predicted sample of (x,y) coordinates predicted based on a linear combination of intra prediction mode and reference samples can be derived as in Equation 1 below. [Formula 1] Here, R x,-1 and R -1,yrepresents the upper reference sample and the left reference sample located above and to the left of the current sample at (x, y) coordinates, and R -1,-1 represents the upper left reference sample located at the upper left corner of the current block. Meanwhile, when PDPC is applied to intra planar mode, intra DC mode, horizontal intra prediction mode, and vertical intra prediction mode, additional boundary filters such as the DC mode boundary filter or vertical / horizontal mode edge filter of the existing HEVC may not be required. Figure 6 shows the reference samples (R) defined in PDPC according to various prediction modes. x,-1 , R -1,y , R -1,-1 ) is indicated. Referring to FIG. 6, in PDPC, reference samples can be derived according to (a) diagonal top-right mode, (b) diagonal bottom-left mode, (c) adjacent diagonal top-right mode, and (d) adjacent diagonal bottom-left mode. The weights of PDPC can be derived based on the prediction modes as shown in [Table 1] below. [Table 1] PDPC generates a prediction sample using a reference sample according to the prediction mode, and then improves the prediction sample using the surrounding reference samples. PDPC can be applied to Planar, DC, Mode 2 (bottom-right direction mode), VDIA (top-left direction mode), Hor (horizontal direction mode), Ver (vertical direction mode), the surrounding modes of Mode 2 (modes 3 to 10), and the surrounding modes of VDIA mode (modes 58 to 65), based on 65 directional intra prediction modes. In addition, instead of being applied to all prediction samples within the block to be encoded, it can be applied variably considering the block size. ISP (Intra Sub-Paritions) Prediction Conventional intra prediction treats the current block to be encoded as a single encoding unit and performs encoding without division. However, the Intra Sub-Partitions (ISP) prediction method divides the current block to be encoded horizontally or vertically and performs intra prediction encoding. At this time, encoding / decoding is performed on each divided block to generate a reconstructed block, which is then used as a reference block for the next divided block. Currently, Intra Sub-Partitions (ISP) can be divided according to block size, as shown in [Table 2] below. [Table 2] The ISP tool can divide luma intra-predicted blocks into two or four subpartitions, either vertically or horizontally, depending on the block size. For example, the minimum block size for ISP is 4x8 (or 8x4). If the block size is larger than 4x8 (or 8x4), the block can be divided into four subpartitions. Figure 7 is a diagram showing an example of how intra sub-partitions are divided. Referring to FIG. 7 and the above [Table 2], a block having a size of 4x8 can be divided into two sub-partitions by being divided horizontally or vertically as shown in (a). Blocks of sizes other than 4x4, 4x8, and 8x4 can be divided into four sub-partitions by being divided horizontally or vertically as shown in (b). The intra sub-partition method generates an MPM (Most Probably Mode) list according to each partitioning method (horizontal partitioning and vertical partitioning) to reduce encoding complexity, and compares the prediction modes in the generated MPM list with the appropriate prediction mode in terms of rate distortion optimization (RDO) to generate the optimal mode. In addition, the intra sub-partition method described above cannot be used when multiple reference line (MRL) intra prediction is used. That is, the intra sub-partition method is applied only when the 0th reference line is used (i.e., the intra_luma_ref_idx value is 0). In addition, the PDPC described above cannot be used when the intra sub-partition method described above is used. The intra-subpartition method first transmits whether intra-subpartitioning is applied on a block-by-block basis, and if the current block uses intra-subpartitioning (intra_subpartitions_mode_flag), it encodes / decodes information (intra_subpartitions_split_flag) on ​​whether it is horizontal or vertical partitioning. When the intra sub-partition method is applied, the intra prediction mode for the current block is applied equally to the sub-partitions, and the intra prediction performance can be improved by deriving and utilizing surrounding reference samples on a sub-partition basis. That is, when the intra sub-partition method is applied, the residual sample processing procedure is performed on a sub-partition basis. In other words, intra prediction samples are derived for each sub-partition, and the residual signal (residual samples) for the corresponding sub-partition is added to obtain restored samples. The residual signal (residual samples) can be derived through a dequantization / inverse transformation procedure, etc., based on the residual information (quantized transform coefficient information or residual coding syntax) in the bitstream described above. That is, prediction samples for the first subpartition and residual samples are derived, and reconstructed samples for the first subpartition can be derived based on the derived prediction samples. In this case, when deriving prediction samples for the second subpartition, some of the reconstructed samples in the first subpartition (e.g., left or upper peripheral reference samples of the second subpartition) can be used as peripheral reference samples for the second subpartition. Similarly, prediction samples and residual samples for the second subpartition can be derived, and based on these, restoration samples for the second subpartition can be derived. In this case, when deriving prediction samples for the third subpartition, some of the restoration samples within the second subpartition (e.g., left or upper peripheral reference samples of the third subpartition) can be used as peripheral reference samples for the third subpartition. The same explanation can be applied to the subsequent subpartitions. Matrix-based Intra Prediction (MIP) Figure 8 is a schematic diagram illustrating a matrix-based intra prediction process. Matrix-based intra prediction (MIP) is also known as affine linear weighted intra prediction (ALWIP) or matrix weighted intra prediction (MWIP). To predict samples within a rectangular block of equal width and height, MIP uses as input a row of reconstructed boundary samples on the left side of the block and a row of reconstructed boundary samples above the block. If reconstructed samples are unavailable, they are generated as in conventional intra prediction. As illustrated in Figure 8, the generation of a prediction signal can be accomplished in the following three steps: 1. In case W=H=4, 4 samples are extracted from the boundary samples by averaging, and in all other cases, 8 samples are extracted from the boundary samples by averaging. 2. After performing matrix-vector multiplication with the averaged samples as input, an offset is added, resulting in a reduction in the prediction signal for the sub-sampled sample set from the original block (Matrix-Vector-Multiplication). 3. The prediction signals at the remaining locations are generated through linear interpolation, which linearly interpolates one step in each direction from the prediction signals of the subsampled set (Interpolation). The matrices and offset vectors required to generate prediction signals (prediction blocks or prediction samples) are taken from three sets of matrices: S0, S1, and S2. Set S0 contains 18 matrices, each with 16 rows and 4 columns. and 18 offset vectors, each with a size of 16. It consists of . The matrices and offset vectors of the set are used for blocks of 4x4 size. Set S1 consists of 10 matrices, each with 16 rows and 8 columns. and 10 offset vectors, each with a size of 16. It consists of . The matrices and offset vectors of the set are used for blocks of sizes 4x8, 8x4, and 8x8. Finally, set S2 consists of 6 matrices, each with 64 rows and 8 columns. and six offset vectors, each with a size of 64 It consists of the matrices and offset vectors of that set or some of these matrices and offset vectors are used for all other block shapes. The total number of multiplications required to compute the matrix vector product is In other words, in MIP mode, up to 4 multiplications are required per sample. DIMD(Decoder side Intra Mode Derivation) In Decoder-side Intra Mode Derivation (DIMD), intra prediction can be derived as a weighted average between the planar and two derived directions. Two angular modes can be selected from the Histogram of Gradients (HoG) calculated from the surrounding pixels of the current block. Once the two angular modes are selected, the predictors of the angular modes and the planar predictor are calculated, and their weighted average is used as the final predictor for the corresponding block. The corresponding amplitudes of the HoG for each of the two modes are used to determine the weights. Since the derived intra modes are included in the initial list of MPMs, the DIMD procedure is performed before the MPM list is constructed. The initial derived intra mode of a DIMD block is stored with the block and can be used to construct the MPM lists of surrounding blocks. FUSION FOR TEMPLATE-BASED INTRA MODE DERIVATION(TIMD) For each intra prediction in the MPM, the Sum of Absolute Transformed Differences (SATD) between the predicted sample and the reconstructed sample in the template is calculated. The first two intra prediction modes with the smallest SATD can be selected as the TIMD mode. These two TIMD modes are weighted and fused, and the weighted intra prediction is used to encode the current CU. PDPC can be included in the derivation of the TIMD mode. The costs of the two selected modes are compared against a threshold and a cost factor of 2 is applied in the test as follows: costMode2 < 2*costMode1. If this condition is true, fusion is applied, otherwise only mode 1 is used. The weights of the modes are calculated from the SATD cost as follows: weight1 = costMode2 / (costMode1+ costMode2) weight2 = 1 - weight1 Spatial Geometric Partitioning Mode (SGPM) SGPM is an intra mode similar to GPM's inter-coding tool, where two prediction parts are generated through the intra prediction process. In this mode, a candidate list is created for each entry, containing one partition and two intra prediction modes. The partition mode and three intra prediction modes are used to form a combination. The candidate list length can be set to 16, and the selected candidate index can be signaled. The candidate list is reordered using templates, where the SAD between the template's prediction and reconstruction is used for alignment. The template size can be fixed to 1. For each partition mode, an IPM list for each part is derived using the same intra-inter GPM list derivation. The size of the IPM list can be set to 3. In the list, the TIMD derivation mode can be replaced by two derivation modes in the horizontal and vertical directions. SGPM mode can be applied with limited block sizes as follows: 4<=width<=64, 4<=height<=64, width <height*8, height<width*8, width*height> =32 Adaptive blending is also used in spatial GPM, and the blending depth τ can be derived as follows: - If min(width, height)==4, 1 / 2 τ is selected - else if min(width, height)==8, τ is selected - else if min(width, height)==16, 2τ is selected - else if min(width, height)==32, 4τ is selected - else, 8τ is selected Intra Block Copy (IBC) IBC is a tool adopted in the HEVC extension of SCC. It is well known for significantly improving the coding efficiency of screen content materials. Since IBC mode is implemented as a block-level coding mode, block matching (BM) can be performed in the encoder to find an optimal block vector (or motion vector) for each CU. Here, the block vector can be used to indicate the displacement from the current block to a reference block already reconstructed within the current block. The luma block vector of an IBD-coded CU can be of integer resolution (or precision). The chroma block vector can be rounded to integer resolution. When combined with AMVR, IBC mode can switch between 1-pel (pixel) and 4-pel (pixel) motion vector resolutions. An IBD-coded CU can be treated as a third prediction mode, rather than an intra- or inter-prediction mode. IBC mode can be applied to CUs with both a width and a height of 64 luma samples or less. On the encoder side, hash-based motion estimation can be performed for IBC. The encoder can perform a block-by-block (BD) check for blocks whose width and height are no greater than 16 luma samples. For non-merge mode, block vector search can be performed first using a hash-based search. If the hash search does not return a valid candidate, a block-matching-based local search can be performed. In hash-based search, the hash key matching (32-bit CRC) between the current block and the reference block can be extended to all allowed block sizes. The hash key calculation for each location in the current picture is based on 4x4 sub-blocks. For larger current blocks, if all the hash keys of the 4x4 sub-blocks match the hash keys of the corresponding reference locations, the hash key can be determined to match that of the reference block. When the hash keys of multiple prediction blocks are found to match those of the current block, the block vector cost of each matched reference is calculated and the minimum cost can be selected. In block matching searches, the search range can be set to cover both previous and current CTUs. At the CU level, the IBC mode is signaled by a flag, which can be signaled as IBC AMVP mode or IBC Skip / Merge mode as follows: - IBC Skip / Merge Mode: A merge candidate index can be used to indicate which block vectors from a list of neighboring candidate IBC coded blocks are used to predict the current block. The merge list can include spatial, HMVP, and pairwise candidates. - IBC AMVP mode: Block vector differences can be coded in the same way as motion vector differences. The block vector prediction method can use two candidates as predictors: one from the left neighbor and one from the upper neighbor (if IBC coded). If neither neighbor is available, the default block can be used as the predictor. A flag can be signaled to indicate the block vector predictor index. Meanwhile, when inter prediction is applied, the prediction unit of the encoding device / decoding device can perform inter prediction on a block-by-block basis to derive prediction samples. Inter prediction can refer to a prediction derived in a manner dependent on data elements (e.g., sample values, or motion information) of pictures other than the current picture. When inter prediction is applied to the current block, a predicted block (prediction sample array) for the current block can be derived based on a reference block (reference sample array) specified by a motion vector on a reference picture pointed to by a reference picture index. At this time, in order to reduce the amount of motion information transmitted in the inter prediction mode, the motion information of the current block can be predicted in units of blocks, sub-blocks, or samples based on the correlation of the motion information between the neighboring blocks and the current block. The motion information may include a motion vector and / or a reference picture index. The motion information may further include information on the inter prediction type (L0 prediction, L1 prediction, Bi prediction, etc.). When inter prediction is applied, the neighboring blocks may include spatial neighboring blocks existing in the current picture and temporal neighboring blocks existing in the reference picture. The reference picture including the above reference block and the reference picture including the temporal neighboring block may be the same or different. The temporal neighboring block may be called a collocated reference block, a collocated CU (colCU), etc., and the reference picture including the temporal neighboring block may be called a collocated picture (colPic). For example, a motion information candidate list may be constructed based on the neighboring blocks of the current block, and a flag or index information indicating which candidate is selected (used) to derive the motion vector and / or reference picture index of the current block may be signaled. Inter prediction can be performed based on various prediction modes. For example, in the case of skip mode and merge mode, the motion information of the current block may be the same as the motion information of the selected neighboring block. In the case of skip mode, unlike the merge mode, a residual signal may not be transmitted. In the case of motion vector prediction (MVP) mode, the motion vector of the selected neighboring block is used as a motion vector predictor, and the motion vector difference may be signaled. In this case, the motion vector of the current block can be derived using the sum of the motion vector predictor and the motion vector difference. The above motion information may include L0 motion information and / or L1 motion information depending on the inter prediction type (L0 prediction, L1 prediction, Bi prediction, etc.). A motion vector in the L0 direction may be called an L0 motion vector or MVL0, and a motion vector in the L1 direction may be called an L1 motion vector or MVL1. Prediction based on an L0 motion vector may be called an L0 prediction, prediction based on an L1 motion vector may be called an L1 prediction, and prediction based on both the L0 motion vector and the L1 motion vector may be called a bi-prediction (Bi). Here, an L0 motion vector may represent a motion vector associated with a reference picture list L0 (L0), and an L1 motion vector may represent a motion vector associated with a reference picture list L1 (L1). The reference picture list L0 may include pictures preceding the current picture in output order as reference pictures, and the reference picture list L1 may include pictures succeeding the current picture in output order. The preceding pictures may be called forward (reference) pictures, and the succeeding pictures may be called backward (reference) pictures. The above reference picture list L0 may further include pictures subsequent to the current picture in output order as reference pictures. In this case, the previous pictures may be indexed first and the subsequent pictures may be indexed next within the reference picture list L0. The above reference picture list L1 may further include pictures previous to the current picture in output order as reference pictures. In this case, the subsequent pictures may be indexed first and the previous pictures may be indexed next within the reference picture list L1. Here, the output order may correspond to a POC (picture order count) order. FIG. 9 and FIG. 10 illustrate examples of inter prediction-based video / image encoding methods to which embodiments of the present disclosure can be applied. Referring to FIG. 9, the encoding device (200) can perform inter prediction for the current block (S600). The encoding device can derive the inter prediction mode and motion information of the current block, and generate prediction samples of the current block. Here, the inter prediction mode determination, motion information derivation, and prediction sample generation procedures may be performed simultaneously, or one procedure may be performed before the other. For example, as illustrated in FIG. 10, the inter prediction unit (221) of the encoding device (200) may include a prediction mode determination unit (221a), a motion information derivation unit (221b), and a prediction sample derivation unit (221c). The prediction mode determination unit (221a) may determine the prediction mode for the current block, the motion information derivation unit (221b) may derive motion information of the current block, and the prediction sample derivation unit (221c) may derive prediction samples of the current block. For example, the inter prediction unit of the encoding device can search for a block similar to the current block within a certain area (search area) of reference pictures through motion estimation, and derive a reference block whose difference from the current block is minimal or below a certain standard. Based on this, a reference picture index indicating a reference picture where the reference block is located can be derived, and a motion vector can be derived based on the positional difference between the reference block and the current block. The encoding device can determine a mode to be applied to the current block among various prediction modes. The encoding device can compare RD costs for the various prediction modes and determine an optimal prediction mode for the current block. For example, when skip mode or merge mode is applied to the current block, the encoding device may configure a merge candidate list described below, and derive a reference block among the reference blocks indicated by the merge candidates included in the merge candidate list, wherein the difference between samples from the current block, i.e., the difference in SAD or SATD, is minimal or below a certain standard. In this case, a merge candidate associated with the derived reference block is selected, and merge index information indicating the selected merge candidate may be generated and signaled to the decoding device. Motion information of the current block may be derived using motion information of the selected merge candidate. As another example, when the (A)MVP mode is applied to the current block, the encoding device may configure an (A)MVP candidate list described below, and use the motion vector of a motion vector predictor (mvp) candidate selected from among motion vector predictor (mvp) candidates included in the (A)MVP candidate list as the motion vector predictor of the current block. In this case, for example, a motion vector pointing to a reference block derived by the above-described motion estimation may be used as the motion vector of the current block, and a motion vector predictor candidate having a motion vector with the smallest difference from the motion vector of the current block among the motion vector predictor candidates may be the selected motion vector predictor candidate. A Motion Vector Difference (MVD), which is the difference obtained by subtracting the motion vector predictor from the motion vector of the current block, may be derived. In this case, information about the MVD may be signaled to the decoding device. In addition, when the (A)MVP mode is applied, the value of the reference picture index may be configured with reference picture index information and signaled separately to the decoding device. The encoding device can derive residual samples based on predicted samples (S610). The encoding device can derive residual samples by comparing the original samples of the current block with the predicted samples. An encoding device can encode image information including prediction information and residual information (S620). The encoding device can output the encoded image information in the form of a bitstream. The prediction information is information related to a prediction procedure and may include prediction mode information (e.g., a skip flag, a merge flag, or a merge index) and / or motion information. The motion information may include candidate selection information (e.g., a merge index, an MVP flag, or an MVP index), which is information for deriving a motion vector. In addition, the motion information may include information about the MVD described above and / or reference picture index information. In addition, the motion information may include information indicating whether L0 prediction, L1 prediction, or bi-prediction is applied. The residual information is information about residual samples. The residual information may include information about quantized transform coefficients for the residual samples. The output bitstream can be stored on a (digital) storage medium and transmitted to a decoding device, or can be transmitted to a decoding device via a network. Meanwhile, as described above, the encoding device can generate a reconstructed picture (including reconstructed samples and reconstructed blocks) based on reference samples and residual samples. This is to derive the same prediction result as that performed by the decoding device from the encoding device, thereby improving coding efficiency. Accordingly, the encoding device can store the reconstructed picture (or reconstructed samples, reconstructed blocks) in memory and use it as a reference picture for inter prediction. As described above, an in-loop filtering procedure, etc. can be further applied to the reconstructed picture. FIGS. 11 and 12 illustrate examples of inter-prediction based video / image decoding methods to which embodiments of the present disclosure can be applied. A video / image decoding procedure based on inter prediction may roughly include, for example: Referring to FIG. 11, the decoding device (300) can perform an operation corresponding to the operation performed in the encoding device (200). The decoding device can perform a prediction on the current block based on the received prediction information and derive prediction samples. Specifically, the decoding device can determine a prediction mode for the current block based on the received prediction information (S700). The prediction mode determination unit (332a) of the decoding device (300) can determine which inter prediction mode is applied to the current block based on the prediction mode information in the prediction information. For example, based on the merge flag, it can be determined whether the current block is subject to merge mode or (A)MVP mode. Alternatively, one of various inter prediction mode candidates can be selected based on the mode index. The inter prediction mode candidates can include skip mode, merge mode, and / or (A)MVP mode, or can include various inter prediction modes described below. The decoding device can derive motion information of the current block based on the determined inter prediction mode (S710). For example, when skip mode or merge mode is applied to the current block, the motion information derivation unit (332b) of the decoding device (300) can construct a merge candidate list described below and select one merge candidate from among the merge candidates included in the merge candidate list. This selection can be performed based on the above-described selection information (merge index). Motion information of the current block can be derived using motion information of the selected merge candidate. Motion information of the selected merge candidate can be used as motion information of the current block. As another example, when the (A)MVP mode is applied to the current block, the decoding device may construct an (A)MVP candidate list described below, and use the motion vector of an MVP candidate selected from among the MVP (motion vector predictor) candidates included in the (A)MVP candidate list as the MVP of the current block. This selection may be performed based on the selection information (mvp flag or mvp index) described above. In this case, the MVD of the current block may be derived based on information about the MVD, and the motion vector of the current block may be derived based on the MVP and MVD of the current block. In addition, the reference picture index of the current block may be derived based on reference picture index information. A picture indicated by a reference picture index within the reference picture list for the current block may be derived as a reference picture referenced for inter prediction of the current block. Meanwhile, as described below, motion information of the current block can be derived without constructing a candidate list, in which case the motion information of the current block can be derived according to the procedure initiated in the prediction mode described below. In this case, constructing a candidate list as described above can be omitted. The decoding device can generate prediction samples for the current block based on the motion information of the current block (S720). In this case, the prediction sample derivation unit (332c) of the decoding device (300) can derive a reference picture based on the reference picture index of the current block, and derive prediction samples of the current block using samples of the reference block pointed to by the motion vector of the current block on the reference picture. In this case, as described below, a prediction sample filtering procedure may be further performed on all or part of the prediction samples of the current block, depending on the case. In other words, the inter prediction unit (332) of the decoding device (300) may include a prediction mode determination unit (332a), a motion information derivation unit (332b), and a prediction sample derivation unit (332c), and may determine a prediction mode for the current block based on the prediction mode information received from the prediction mode determination unit (332a), derive motion information (motion vector and / or reference picture index, etc.) of the current block based on the information about motion information received from the motion information derivation unit (332b), and derive or generate prediction samples of the current block from the prediction sample derivation unit (332c). The decoding device generates residual samples for the current block based on the received residual information (S730). The decoding device (300) generates restoration samples for the current block based on the prediction samples and residual samples, and can generate a restoration picture based on these (S740). As described above, in-loop filtering procedures, etc. may be further applied to the restoration picture. FIG. 13 exemplarily illustrates an inter prediction procedure to which an embodiment of the present disclosure can be applied. Referring to FIG. 13, the inter prediction procedure (S600) described above may include an inter prediction mode determination step, a motion information derivation step according to the determined prediction mode, and a prediction performance (prediction sample generation) step based on the derived motion information. The inter prediction procedure may be performed in an encoding device and a decoding device as described above. In this document, a coding device may include an encoding device and / or a decoding device. Referring to FIG. 13, the coding device determines an inter prediction mode for a current block (S800). Various inter prediction modes can be used to predict the current block within a picture. For example, various modes such as merge mode, skip mode, MVP (Motion Vector Prediction) mode, affine mode, sub-block merge mode, and MMVD (Merge with MVD) mode can be used. Decoder side Motion Vector Refinement (DMVR) mode, Adaptive Motion Vector Resolution (AMVR) mode, bi-prediction with CU-level Weight (BCW), bi-directional optical flow (BDOF), etc. can be used as auxiliary modes. In addition, according to one embodiment of the present disclosure, the above-described inter prediction mode can include a multi-hypethesis prediction (MHP) mode. The multi-hypethesis prediction mode represents a method of performing prediction by weighting an additional prediction block generated based on additional motion information to an inter prediction block. The multi-home prediction mode is described in detail below. In the present disclosure, the affine mode may be referred to as the affine motion prediction mode. In addition, the MVP mode may be referred to as the Advanced Motion Vector Prediction (AMVP) mode. In the present disclosure, motion information candidates derived from some modes and / or some modes may be included as one of the motion information-related candidates of other modes. For example, an HMVP candidate may be added as a merge candidate of the merge / skip mode, or may be added as a motion vector predictor candidate of the AMVP mode. When an HMVP candidate is used as a motion information candidate of the merge mode or the skip mode, the HMVP candidate may be referred to as an HMVP merge candidate. Prediction mode information indicating the inter-prediction mode of the current block can be signaled from the encoding device to the decoding device. The prediction mode information can be included in the bitstream and received by the decoding device. The prediction mode information can include index information indicating one of multiple candidate modes. Alternatively, the inter-prediction mode can be indicated through hierarchical signaling of flag information. In this case, the prediction mode information may include one or more flags. For example, a skip flag may be signaled to indicate whether skip mode is applied, a merge flag may be signaled to indicate whether merge mode is applied when skip mode is not applied, and MVP mode may be indicated to be applied when merge mode is not applied, or additional flags may be signaled for additional distinction. Affine mode may be signaled as an independent mode, or as a mode dependent on merge mode or MVP mode. For example, an affine mode may include an affine merge mode and an affine MVP mode. The coding device can derive motion information for the current block (S810). The motion information can be derived based on the inter-prediction mode determined in the aforementioned step. The coding device can perform inter-prediction using the motion information of the current block. The encoding device can derive optimal motion information for the current block through a motion estimation procedure. For example, an encoding device can use an original block within an original picture for a current block to search for a similar reference block with a high correlation within a predetermined search range within the reference picture in fractional pixel units, thereby deriving motion information. The similarity of blocks can be derived based on the difference in phase-based sample values. For example, the similarity of blocks can be calculated based on the SAD between the current block (or a template of the current block) and the reference block (or a template of the reference block). In this case, motion information can be derived based on the reference block with the smallest SAD within the search range. The derived motion information can be signaled to a decoding device in various ways based on an inter prediction mode. The coding device can perform inter prediction based on motion information for the current block to generate prediction samples (S820). The current block containing the prediction samples may be referred to as a prediction block. Meanwhile, information indicating whether the above-described List0 (L0) prediction, List1 (L1) prediction, or bi-prediction is used for the current block (current coding unit) can be signaled. This information may be called motion prediction direction information, inter-prediction direction information, or inter-prediction indication information, and may be configured / encoded / signaled, for example, in the form of an inter_pred_idc syntax element. That is, the inter_pred_idc syntax element can indicate whether the above-described List0 (L0) prediction, List1 (L1) prediction, or bi-prediction is used for the current block (current coding unit). In this document, for the convenience of explanation, the inter-prediction type (L0 prediction, L1 prediction, or BI prediction) indicated by the inter_pred_idc syntax element may be represented as motion prediction direction. L0 prediction may be represented as pred_L0, L1 prediction as pred_L1, and bi-prediction as pred_BI. For example, depending on the value of the inter_pred_idc syntax element, the prediction type can be indicated as in Table 3 below. [Table 3] As described above, a picture may include one or more slices. A slice may have one of the following types: intra (I) slice, predictive (P) slice, and bi-predictive (B) slice. The slice type may be indicated based on slice type information. For blocks within an I slice, inter prediction is not used for prediction, and only intra prediction can be used. Of course, even in this case, the original sample values ​​can be coded and signaled without prediction. For blocks within a P slice, either intra prediction or inter prediction can be used, and when inter prediction is used, only uni prediction can be used. On the other hand, for blocks within a B slice, either intra prediction or inter prediction can be used, and when inter prediction is used, up to bi prediction can be used. L0 and L1 may include reference pictures encoded / decoded before the current picture. For example, L0 may include reference pictures that are before and / or after the current picture in POC order, and L1 may include reference pictures that are after and / or before the current picture in POC order. In this case, L0 may be assigned a relatively lower reference picture index to reference pictures that are before the current picture in POC order, and L1 may be assigned a relatively lower reference picture index to reference pictures that are after the current picture in POC order. For B slices, bi-prediction may be applied, and in this case, either uni-directional bi-prediction or bi-directional bi-prediction may be applied. Bi-directional bi-prediction may be called true bi-prediction. Inter prediction can be performed using motion information of the current block. The encoding device can derive optimal motion information for the current block through a motion estimation procedure. For example, the encoding device can search for similar reference blocks with high correlation within a predetermined search range within the reference picture using the original block within the original picture for the current block, in fractional pixel units, and thereby derive motion information. The similarity between blocks can be derived based on the difference in phase-based sample values. For example, the similarity between blocks can be calculated based on the SAD between the current block (or a template of the current block) and the reference block (or a template of the reference block). In this case, motion information can be derived based on the reference block with the smallest SAD within the search range. The derived motion information can be signaled to the decoding device in various ways based on the inter prediction mode. Merge mode and skip mode When merge mode is applied, the motion information of the current prediction block is not directly transmitted, but the motion information of the surrounding prediction blocks is used to derive the motion information of the current prediction block. Therefore, the motion information of the current prediction block can be indicated by transmitting flag information indicating that merge mode is used and a merge index indicating which surrounding prediction block was used. The merge mode may also be called regular merge mode. To perform merge mode, the encoder can search for merge candidate blocks to derive motion information of the current prediction block. For example, up to five merge candidate blocks can be used, but the present invention is not limited thereto. In addition, the maximum number of merge candidate blocks can be transmitted in the slice header or tile group header, but the present invention is not limited thereto. After finding the merge candidate blocks, the encoder can generate a merge candidate list, and select the merge candidate block with the lowest cost among them as the final merge candidate block. Figure 14 is a diagram showing examples of blocks used to construct a merge candidate list. The present invention provides various embodiments for merge candidate blocks constituting a merge candidate list. The merge candidate list may utilize, for example, five merge candidate blocks. For example, four spatial merge candidates and one temporal merge candidate may be utilized. As a specific example, in the case of spatial merge candidates, the blocks illustrated in Fig. 14 may be utilized as spatial merge candidates. Hereinafter, the spatial merge candidates or the spatial MVP candidates described below may be referred to as SMVPs, and the temporal merge candidates or the temporal MVP candidates described below may be referred to as TMVPs. The list of merge candidates for the current block can be constructed based on, for example, the following procedure: - Insert spatial merge candidates derived by exploring spatial surrounding blocks into the merge candidate list. - Insert the temporal merge candidates derived by exploring the temporal surrounding blocks into the merge candidate list. - Compare the number of current merge candidates with the maximum number of merge candidates. - If the number of current merge candidates is less than the maximum number of merge candidates, insert additional merge candidates into the merge candidate list. Specifically, the coding device (encoder / decoder) searches the spatial neighboring blocks of the current block and inserts the derived spatial merge candidates into a merge candidate list. For example, the spatial neighboring blocks may include the lower left corner neighboring blocks, the left neighboring blocks, the upper right corner neighboring blocks, the upper neighboring blocks, and the upper left corner neighboring blocks of the current block. However, this is merely an example, and in addition to the spatial neighboring blocks described above, additional neighboring blocks such as the right neighboring blocks, the lower neighboring blocks, and the lower right neighboring blocks may be further used as the spatial neighboring blocks. The coding device may search the spatial neighboring blocks based on priorities to detect available blocks and derive motion information of the detected blocks as spatial merge candidates. For example, the encoder and decoder may search the five blocks illustrated in FIG. 14 in the order of A1, B1, B0, A0, and B2, and sequentially index the available candidates to form a merge candidate list. The coding device searches the temporal neighboring blocks of the current block and inserts the derived temporal merge candidates into the merge candidate list. The temporal neighboring blocks may be located on a reference picture that is different from the current picture where the current block is located. The reference picture where the temporal neighboring blocks are located may be called a collocated picture or col picture. The temporal neighboring blocks may be searched in the order of the lower right corner neighboring blocks and the lower right center block of the co-located block of the current block in the col picture. Meanwhile, when motion data compression is applied, specific motion information can be stored as representative motion information for each storage unit in a col picture. In this case, there is no need to store motion information for all blocks within a certain storage unit, and thus, a motion data compression effect can be obtained. In this case, a certain storage unit may be predetermined, for example, a 16x16 sample unit or an 8x8 sample unit, or size information for a certain storage unit may be signaled from the encoder to the decoder. When motion data compression is applied, the motion information of a temporal neighboring block may be replaced with representative motion information of a certain storage unit where the temporal neighboring block is located. That is, in terms of implementation, a temporal merge candidate may be derived based on the motion information of a prediction block that covers a position that is arithmetically shifted to the right by a certain value based on the coordinates of the temporal neighboring block (upper left sample position), rather than a prediction block located at the coordinates of the temporal neighboring block. For example, if the certain storage unit is 2 n x2 nIn the case of sample units, if the coordinates of the temporal surrounding block are (xTnb, yTnb), then the modified position is ((xTnb>>n)<<n), (yTnb> >n)< <n))에 위치하는 예측 블록의 움직임 정보가 시간적 머지 후보를 위하여 사용될 수 있다. 구체적으로 예를 들어, 일정 저장 단위가 16x16 샘플 단위인 경우, 시간적 주변 블록의 좌표가 (xTnb, yTnb)라 하면, 수정된 위치인 ((xTnb> >4)<<4), (yTnb>>4)<<4)) motion information of the prediction block located at can be used for the temporal merge candidate. Or, for example, if the storage unit is an 8x8 sample unit and the coordinates of the temporal neighboring block are (xTnb, yTnb), the motion information of the prediction block located at the modified position ((xTnb>>3)<<3), (yTnb>>3)<<3)) can be used for the temporal merge candidate. The coding device can compare the current number of merge candidates with the maximum number of merge candidates. The maximum number of merge candidates can be predefined or signaled from the encoder to the decoder. For example, the encoder can generate information regarding the maximum number of merge candidates, encode it, and transmit it to the decoder in bitstream form. Once the maximum number of merge candidates is reached, the subsequent candidate addition process may not proceed. If the comparison result shows that the number of current merge candidates is less than the maximum number of merge candidates, the coding device inserts an additional merge candidate into the merge candidate list. The additional merge candidate may include, for example, at least one of the following: history-based merge candidate(s), pair-wise average merge candidate(s), ATMVP, combined bi-predictive merge candidate (if the slice / tile group type of the current slice / tile group is type B), and / or zero-vector merge candidate. If the comparison result shows that the number of current merge candidates is not less than the maximum number of merge candidates, the coding device can terminate the construction of the merge candidate list. In this case, the encoder can select the optimal merge candidate among the merge candidates constituting the merge candidate list based on the RD (rate-distortion) cost and signal the selection information (e.g., merge index) indicating the selected merge candidate to the decoder. The decoder can select the optimal merge candidate based on the merge candidate list and the selection information. As described above, the motion information of the selected merge candidate can be used as the motion information of the current block, and prediction samples of the current block can be derived based on the motion information of the current block. The encoder can derive residual samples of the current block based on the prediction samples, and can encode residual information about the residual samples and transmit them to the decoder. As described above, the decoder can generate reconstructed samples based on the residual samples and prediction samples derived based on the transmitted residual information, and generate a reconstructed picture based on the reconstructed samples. When skip mode is applied, motion information for the current block can be derived in the same way as when merge mode is applied. However, when skip mode is applied, the residual signal for the corresponding block is omitted, so the predicted samples can be used directly as restored samples. Merge mode with MVD (MMVD) This section describes the MMVD mode mentioned above. In addition to Merge mode, which directly uses implicitly derived motion information for the prediction samples of the current block, Merge mode (MMVD) can also be used. Since similar motion information derivation methods are used in Skip mode and Merge mode, MMVD can also be applied to Skip mode. After signaling the Skip flag and Merge flag, MMVD flag information (e.g., mmvd_flag) can be signaled to indicate whether MMVD mode is to be used for the current block. In MMVD, after a merge candidate is selected, the candidate can be further refined based on the signaled MVD information. When MMVD is applied to the current block (i.e., when mmvd_flag is 1), additional information about MMVD can be signaled. The additional information can include a merge candidate flag (e.g., mmvd_merge_flag) indicating whether the first or second candidate in the merge candidate list is used with the motion vector difference, a distance index indicating the motion magnitude (e.g., mmvd_distance_idx), and a direction index indicating the motion direction (e.g., mmvd_direction_idx). In MMVD mode, one of the first two candidates in the merge list can be selected to be used as the MV reference. The merge candidate flag is signaled to indicate which candidate is used. The distance index represents motion size information and a predefined offset from the starting point. The offset is added to the horizontal or vertical component of the starting MV. The relationship between the distance index and the predefined offset is shown in Table 4 below. [Table 4] Here, if slice_fpel_mmvd_enabled_flag is 1, it indicates that the merge mode with motion vector difference uses integer sample precision in the current slice. If slice_fpel_mmvd_enabled_flag is 0, it indicates that the merge mode with motion vector difference can use fractional sample precision in the current slice. The slice_fpel_mmvd_enabled_flag syntax element can be signaled via the slice header or included in the slice header. The direction index indicates the direction of the MVD with respect to the starting point. The direction index can indicate one of four directions, as shown in Table 5 below. The meaning of the MVD symbol may vary depending on the information of the starting MV. If the starting MV is a non-predicted MV or both lists are bidirectional MVs pointing to the same side of the current picture (i.e., the POCs of the two references are both greater than or less than the POC of the current picture), the sign in Table 5 below can indicate the sign of the MV offset added to the starting MV. If the starting MVs are bidirectional predictive MVs and the two MVs point to different sides of the current picture (i.e., the POC of one reference is greater than the POC of the current picture, and the POC of the other reference is less than the POC of the current picture), the sign in Table 5 below indicates the sign of the MV offset added to the MV element of List 0 of the starting MV, and the sign of List 1 MV has the opposite value. [Table 5] The two elements of the merge plus MVD offset MmvdOffset[x0][y0] can be derived as follows: - MmvdOffset[ x0 ][ y0 ]

[0000] = ( MmvdDistance[ x0 ][ y0 ] << 2 ) * MmvdSign[ x0 ][ y0 ][0] - MmvdOffset[ x0 ][ y0 ]

[0001] = ( MmvdDistance[ x0 ][ y0 ] << 2 ) * MmvdSign[ x0 ][ y0 ][1] MVP (Motion Vector Prediction) The MVP (Motion Vector Prediction) mode may also be referred to as the AMVP (advanced motion vector prediction) mode. When the MVP mode is applied, a motion vector predictor (mvp) candidate list can be generated using the motion vectors of the reconstructed spatial neighboring blocks and / or the motion vectors corresponding to the temporal neighboring blocks (or Col blocks). That is, the motion vectors of the reconstructed spatial neighboring blocks and / or the motion vectors corresponding to the temporal neighboring blocks can be used as motion vector predictor candidates. When paired prediction is applied, an mvp candidate list for deriving L0 motion information and an mvp candidate list for deriving L1 motion information can be generated and used separately. The above-described prediction information (or information regarding prediction) may include selection information (e.g., MVP flag or MVP index) indicating an optimal motion vector predictor candidate selected from among the motion vector predictor candidates included in the list. In this case, the prediction unit may use the selection information to select a motion vector predictor of the current block from among the motion vector predictor candidates included in the motion vector candidate list. The prediction unit of the encoding device can obtain a motion vector difference (MVD) between the motion vector of the current block and the motion vector predictor, and can encode and output it in the form of a bitstream. That is, the MVD can be obtained as a value obtained by subtracting the motion vector predictor from the motion vector of the current block. At this time, the prediction unit of the decoding device can obtain the motion vector difference included in the information regarding the prediction, and derive the motion vector of the current block through the addition of the motion vector difference and the motion vector predictor. The prediction unit of the decoding device can obtain or derive a reference picture index indicating a reference picture, etc. from the information regarding the prediction. For example, a motion vector predictor candidate list can be configured as follows: - Search for spatial candidate blocks for motion vector prediction and insert them into the prediction candidate list. - Check if the number of spatial candidate blocks is less than 2 - If the number of spatial candidate blocks is less than 2, search for temporal candidate blocks and insert them into the prediction candidate list. - If no temporal candidate block is available, use zero motion vector. - If the number of spatial candidate blocks is not less than 2, the construction of the motion vector predictor candidate list is terminated. Meanwhile, when the MVP mode is applied, the reference picture index can be explicitly signaled. In this case, the reference picture index for L0 prediction (refidxL0) and the reference picture index for L1 prediction (refidxL1) can be signaled separately. For example, when the MVP mode is applied and bi-prediction (BI prediction) is applied, both information about refidxL0 and information about refidxL1 can be signaled. Motion Vector Difference (MVD) coding When the MVP mode is applied, information about the MVD derived from the encoding device as described above can be signaled or encoded and transmitted to the decoding device. The information about the MVD can include, for example, information indicating x and y components for the MVD absolute value and sign. In this case, information indicating whether the MVD absolute value is greater than 0 and greater than 1, and the MVD remainder can be signaled in stages. For example, information indicating whether the MVD absolute value is greater than 1 can be signaled only when the value of the flag information indicating whether the MVD absolute value is greater than 0 is 1. For example, information about an MVD can be encoded in an encoding device and signaled to a decoding device using the following syntax: [Table 6] For example, MVD[compIdx] can be derived based on abs_mvd_greater0_flag[compIdx] * ( abs_mvd_minus2[compIdx] + 2 ) * ( 1 2 * mvd_sign_flag[compIdx]). Here, compIdx (or cpIdx) represents the index of each component and can have the value 0 or 1. A compIdx value of 0 can represent the x component, and a compIdx value of 1 can represent the y component. However, this is just an example, and values ​​for each component can be represented using a coordinate system other than the x, y coordinate system. Meanwhile, MVD for L0 prediction (MVDL0) and MVD for L1 prediction (MVDL1) may be signaled separately, and information about MVD may include information about MVDL0 and / or information about MVDL1. For example, if MVP mode and BI prediction are applied to the current block, information about MVDLO and information about MVDL1 may both be signaled. Affine Prediction Existing video coding systems use only a single motion vector (using a translation motion model) to represent the motion of a coded block. While this method can optimally represent motion at the block level, it does not accurately represent the optimal motion for each pixel. Therefore, determining the optimal motion vector at the pixel level can improve encoding efficiency. To achieve this, we describe an affine motion prediction method that uses an affine motion model to encode the data. Figure 15 is a diagram showing four movements that can be expressed in the affine movement model. Affine motion prediction methods can express motion vectors at each pixel unit of a block using two, three, or four motion vectors. The affine motion model can express four types of motion, as illustrated in Fig. 15. The affine motion model that expresses three types of motion (translation, scale, and rotation) among the motions that the affine motion model can express is called a similarity (or simplified) affine motion model, and the proposed methods are described below based on the similarity affine motion model. However, the disclosed embodiments are not limited to the motion model. Figure 16 is a diagram showing an example of a control point motion vector used in affine motion prediction. As illustrated in Figure 16, affine motion prediction can determine the motion vector of the pixel position included in the block using two or more control point motion vectors (CPMV). At this time, the set of motion vectors is called an affine motion vector field (MVF) and can be determined by the equations below. For the 4-parameter affine motion model, the motion vector at the sample location (x,y) of the block can be derived by Equation 2 below. [Formula 2] For the 6-parameter affine motion model, the motion vector at the sample location (x,y) of the block can be derived by Equation 3 below. [Formula 3] Here is the CPMV of the CP at the top-left corner of the coding block. is the CPMV of the CP at the top-right corner location, is the CPMV of the CP at the bottom-left corner location. And W corresponds to the width of the current block, H corresponds to the height of the current block, is the motion vector at position {x, y}. In the encoding / decoding process, the affine MVF can be determined in units of pixels or pre-defined subblocks. When determined in units of pixels, a motion vector is obtained based on each pixel value, and when determined in units of subblocks, the motion vector of the corresponding block is obtained based on the pixel value at the center of the subblock (the lower right side of the center, i.e., the lower right sample among the four central samples). For example, as illustrated in Fig. 16, it is possible for the affine MVF to be determined in units of 4x4 subblocks. However, this is merely an example, and the size of the subblock applied to affine prediction can be varied. When affine prediction is available, the motion models applicable to the current block can include three models: a translational motion model, a 4-parameter affine motion model, and a 6-parameter affine motion model. Here, the translational motion model can represent a model in which existing block-level motion vectors are used, the 4-parameter affine motion model can represent a model in which two CPMVs are used, and the 6-parameter affine motion model can represent a model in which three CPMVs are used. Affine motion prediction may include affine MVP (or affine inter) mode and affine merge. In affine motion prediction, the motion vectors of the current block can be derived on a sample-by-sample or sub-block-by-subblock basis. Affine merge In affine merge mode, CPMV can be determined based on the affine motion model of neighboring blocks coded using affine motion prediction. Neighboring blocks affine-coded in search order can be used in affine merge mode. If one or more neighboring blocks are coded using affine motion prediction, the current block can be coded using affine merge. That is, when the affine merge mode is applied, the CPMVs of the current block can be derived using the CPMVs of the surrounding blocks. In this case, the CPMVs of the surrounding blocks can be used as the CPMVs of the current block as they are, or the CPMVs of the surrounding blocks can be modified based on the size of the surrounding blocks and the size of the current block and then used as the CPMVs of the current block. Meanwhile, in the case of affine merge where MV is derived in units of subblocks, it can be called subblock merge mode, and this can be indicated based on the merge subblock flag (merge_subblock_flag (value 1)). In this case, the affine merging candidate list described later can also be called a subblock merging candidate list. In this case, the subblock merging candidate list can further include a candidate derived by SbTMVP. In this case, the candidate derived by sbTMVP can be used as the candidate for index 0 of the subblock merging candidate list. In other words, the candidate derived by sbTMVP can be positioned before the inherited affine candidates and constructed affine candidates described later in the subblock merging candidate list. When affine merge mode is applied, an affine merge candidate list may be constructed to derive CPMVs for the current block. The affine merge candidate list may include, for example, at least one of the following candidates: 1) Inherited affine candidates 2) Constructed affine candidates 3) Zero MVs candidates Here, the inherited affine candidate is a candidate derived based on the CPMVs of the surrounding blocks when the surrounding blocks are coded in affine mode, the constructed affine candidate is a candidate derived by constructing CPMVs based on the MVs of the corresponding CP surrounding blocks for each CPMV unit, and the zero MVs candidate can represent a candidate composed of CPMVs whose value is 0. For example, the zero MVs candidate can be optionally inserted into the candidate list when the number of current candidates is less than the number of maximum candidates. Figure 17 is an example showing the positions of candidates in the configured affine merge mode. Two inherited affine candidates can be derived from the affine motion model of the surrounding blocks: one from the left surrounding CUs, and the other from the upper CUs. Referring back to Figure 14 described above, for the left predictor, the scanning order is A0 -> A1, and for the upper predictor, the scanning order is B0 -> B1 -> B2. Only the first inherited candidate on each side can be selected, and no pruning check is performed between the two inherited candidates. Once the surrounding affine CUs are identified, the control point motion vectors are used to derive CPMVP candidates from the affine merge list of the current CU. Referring to Figure 17, when the surrounding lower-left block A is coded in affine mode, the motion vectors v2, v3, and v4 of the upper-left corner, upper-right corner, and lower-left corner of the CU containing block A are obtained. When block A is coded with a 4-parameter affine model, two CPMVs of the current CU are calculated according to v2 and v3. When block A is coded with a 6-parameter affine model, three CPMVs of the current CU are calculated according to v2, v3, and v4. Figure 18 is a drawing showing an example of surrounding blocks for the current block. The constructed affine candidate refers to a candidate constructed by combining neighbor translational motion information of each control point. The motion information for the control point can be derived from the specified spatial and temporal surroundings, as illustrated in Fig. 18. CPMV k (k=1, 2, 3, 4) represents the kth control point. For CPMV1, blocks B2 -> B3 -> A2 are checked in that order, and the MV of the first available block is used. For CPMV2, blocks B1 -> B0 are checked in that order, and for CPMV3, blocks A1 -> A0 are checked in that order. TMVP can be used as CPMV4 if available. After acquiring the MVs for the four control points, affine merge candidates can be constructed based on motion information. The following combinations of control point MVs can be used sequentially for construction: {CPMV1, CPMV2, CPMV3}, {CPMV1, CPMV2, CPMV4}, {CPMV1, CPMV3, CPMV4}, {CPMV2, CPMV3, CPMV4}, {CPMV1, CPMV2}, {CPMV1, CPMV3} A combination of three CPMVs forms a six-parameter affine merge candidate, and a combination of two CPMVs forms a four-parameter affine merge candidate. To avoid the motion scaling procedure, if the reference indices of the control points are different, the corresponding combination of control point MVs is not used. Decoder side Motion Vector Refinement (DMVR) Decoder-side Motion Vector Refinement (DMVR) is a method for motion prediction that refines the motion information of surrounding blocks at the decoder side. When DMVR is applied, the decoder can derive improved motion information through cost comparison based on templates generated using motion information from surrounding blocks in merge / skip mode. This improves motion prediction accuracy and compression performance without requiring additional signaling information. In this disclosure, for convenience of explanation, the decoder is mainly described, but DMVR can be performed in the same manner in the encoder as well. Meanwhile, DMVR can be viewed as an example of a motion information derivation procedure in that motion vectors are improved, and an example of a prediction sample generation procedure in that prediction samples are generated based on the reference blocks pointed to by the improved MV pairs. In the bi-prediction procedure, an improved MV can be searched based on the initial MVs in the reference picture lists L0 and L1. The BM method computes the distortion between two candidate blocks in the reference picture lists L0 and L1. The SAD is calculated for each MV candidate within the search range around the initial MV. The MV candidate with the lowest SAD becomes the improved MV and is used to generate a bi-predicted signal. In one embodiment, the decoder may perform the DMVR process to improve the accuracy of the initial motion compensation prediction (i.e., motion compensation prediction via the conventional merge / skip mode). For example, the decoder may perform the DMVR process when the prediction mode of the current block is merge mode or skip mode, and bidirectional bi-prediction is applied to the current block, where the reference picture is in the opposite direction in display order relative to the current picture. For example, DMVR can be applied to CUs coded according to the following modes and features: - CU-level merge mode using bi-prediction MV - Based on the current picture, one reference picture is a past (previous) picture, and the other reference picture is a future (future) picture. - The distance from the two reference pictures to the current picture (i.e. POC difference) is the same. - CU contains more than 64 luma samples - Both CU height and CU width are equal to or greater than 8 luma samples. - BCW weight index indicates equal weight - WP is not available for the current block - The improved MV derived by the DMVR process is used to generate inter prediction samples and can also be used for temporal motion vector prediction for the next picture coding. The original MV is used in the deblocking process and can also be used for spatial motion vector prediction for future CU coding. Geometric partitioning mode (GPM) In VVC, GPM can be supported for inter prediction. GPM is a type of merge mode that can be signaled using a CU-level flag. Other merge modes can include regular merge mode, MMVD mode, CIIP mode, and sub-block merge mode. Each possible CU size is wxh = 2. m x 2 n A total of 64 partitions can be supported. Here, , 8x64 and 64x8 are excluded. When this mode is used, a CU can be divided into two parts by a geometrically positioned straight line. The location of the division line can be mathematically derived from the angle and offset parameters of a specific partition. Each part of the geometric partition of the CU can be inter-predicted using its own motion. Only a single prediction is allowed for each partition, i.e., each part has one motion vector and one reference index. A uni-prediction motion constraint can be applied to ensure that only two motion-compensated predictions are required for each CU, similar to conventional bi-prediction. Figure 19 illustrates GPM segments grouped at the same angle as an example. A single predicted motion for each partition can be derived using a process as illustrated in Fig. 19. When GPM is used for the current block, a geometric partition index indicating the partition mode of the geometric partition (angle and offset) and two merge indices (one for each partition) can be additionally signaled. The maximum number of GPM candidate sizes can be explicitly signaled in the SPS, and the syntax binarization of the GPM merge indices can be specified. After predicting each part of the geometric partition, the sample values ​​along the geometric partitioning edge can be adjusted using adaptive weighted blending processing, such as blending along the geometric partitioning edge described below. This is a prediction signal for the entire CU, and the transform and quantization processes can be applied to the entire CU as in other prediction modes. Finally, the motion field of the CU predicted using GPM can be stored in the motion field storage for the GPM geometric partitioning mode. Combined inter and intra prediction (CIIP) Combined inter and intra prediction (CIIP) may be applied to the current block. An additional flag (e.g., ciip_flag) may be signaled to indicate whether the CIIP mode applies to the current CU. For example, when the CU is coded in merge mode, if the CU contains at least 64 luma samples (i.e., the product of the CU width and the CU height is greater than or equal to 64), and both the CU width and the CU height are less than 128 luma samples, the additional flag may be signaled to indicate whether the CIIP mode applies to the current CU. CIIP prediction combines inter-prediction signals and intra-prediction signals. The inter-prediction signal P_inter in CIIP mode can be derived using the same inter-prediction process applied in regular merge mode, and the intra-prediction signal P_intra can be derived according to the regular intra-prediction process in planar mode. The intra- and inter-prediction signals can then be combined using a weighted average. Figure 20 illustrates examples of upper-left neighboring blocks used in CIIP weight derivation. Here, the weight values ​​can be calculated as follows depending on the coding modes of the upper-left neighboring blocks: - If the upper neighbor is available and intra-coded, isIntraTop is set to 1, otherwise isIntraTop is set to 0. - If the left neighbor is available and intra-coded, isIntraLeft is set to 1, otherwise isIntraLeft is set to 0. - If (isIntraTop + isIntraLeft) is 2, wt is set to 3 - Otherwise, if (isIntraTop + isIntraLeft) is 1, wt is set to 2; - Otherwise, wt is set to 1 The CIIP prediction can be constructed as shown in Equation 4 below. [Formula 4] GPM including inter and intra prediction In a GPM that includes inter- and intra-prediction, final predicted samples can be generated by weighting the inter-predicted samples and intra-predicted samples for each GPM-separated region. The inter-predicted samples are derived from the inter-GPM, while the intra-predicted samples can be derived from an intra-prediction mode (IPM) candidate list and an index signaled from the encoder. The IPM candidate list size can be predefined as 3. Figure 21 illustrates available IPM candidates for GPM including inter and intra prediction. Available IPM candidates can be parallel angular mode (Parallel mode), perpendicular angular mode (Perpendicular mode), and planar mode with respect to the GPM block boundary, as illustrated in (a), (b), and (c) of Fig. 21. Furthermore, as illustrated in (d) of Fig. 21, GPMs including inter and intra prediction can be restricted to reduce signaling overhead for IPMs and prevent an increase in the intra prediction circuit size of the hardware decoder. In addition, direct motion vector and IPM storage in the GPM blending region can be introduced to further improve coding performance. In DIMD and adjacent mode-based IPM derivation, parallel modes can be registered first. Therefore, if there are no identical IPM candidates in the list, up to two IPM candidates derived from the decoder-side intra-mode derivation (DIMD) method and / or neighboring blocks can be registered. In deriving the neighbor mode, there are up to five locations for the available neighbor blocks, but this may be limited by the GPM block boundary angles already used in GPM using template matching (GPM-TM). Table 7 shows the locations of available neighboring blocks for deriving IPM candidates according to the GPM block boundary angle. A and L can represent the upper and left sides of the predicted block. [Table 7] GPM-Intra can be combined with GPM-MMVD (GPM with merge with motion vector difference). To further improve coding performance, TIMD can be used to generate IPM candidates for GPM-Intra. Parallel modes can be registered first, followed by TIMD, DIMD, and IPM candidates from neighboring blocks. Multi-Hypothesis Prediction (MHP) In multi-home inter prediction mode, one or more additional motion-compensated prediction signals are signaled in addition to the existing bidirectional prediction signal, and the resulting overall prediction signal can be obtained by sample-wise weighted superposition. Bidirectional prediction signal p bi And using the first additional inter prediction signal / assumption h3, the resulting prediction signal p3 can be obtained as follows. [Formula 5] The weight factor α can be specified by a new syntax element add_hyp_weight_idx according to the mapping shown in Table 8 below. [Table 8] Similarly, one or more additional prediction signals can be used. The resulting overall prediction signal can be iteratively accumulated with each additional signal, as in Equation 6 below. [Formula 6] The resulting overall prediction signal is the final p n (i.e. p with the largest index n n ) can be obtained. For example, up to two additional prediction signals can be used (i.e., n is limited to 2). The motion parameters of each additional prediction hypothesis can be explicitly signaled by specifying the reference index, the motion vector predictor index, and the motion vector difference, or implicitly signaled by specifying the merge index. A separate multi-hypothesis merge flag can distinguish these two signaling modes. For the inter AMVP mode, MHP can be applied only when non-equal weights of BCW are selected in the bi-prediction mode. A combination of MHP and BDOF is possible, but BDOF can only be applied to the bidirectional signal part of the prediction signal (i.e., the two common first assumptions). Overlapped block motion compensation (OBMC) OBMC can be performed on all motion compensated block boundaries, including the right and bottom boundaries of a CU. Therefore, it can be applied to both luma and chroma components. To uniformly process CU / sub-block boundaries, OBMC can be performed at the sub-block level for all MC (Motion Compensation) block boundaries. Figure 22 illustrates sub-blocks at CU / PU boundaries and sub-PUs in ATMVP mode as examples. Here, the size of the sub-block can be set to 4x4. When OBMC is applied to a current sub-block, in addition to the current motion vectors, four connected neighboring sub-blocks that are available and not identical to the current motion vectors can also be used to derive a prediction block for the current sub-block. These multiple prediction blocks based on multiple motion vectors can be weighted to generate the final prediction signal for the current sub-block. P is a prediction block based on the motion vector of the neighboring sub-block. N (where N represents the indices of the neighboring sub-blocks up, down, left, and right), and the prediction block based on the motion vectors of the current block is P. C It is expressed as P N Go P C When belonging to the same PU (because they contain the same motion information), OBMC is P N may not be performed from. Otherwise, P N All pixels of P C can be added to the same pixel of P. That is, P N 4 rows / columns of P C can be added to P. The weighting factors {1 / 4, 1 / 8, 1 / 16, 1 / 32} are N, and the weighting factors {3 / 4, 7 / 8, 15 / 16, 31 / 32} are P C can be used in. The exception is P N Only two rows / columns of P C are small MC blocks added to the CU (i.e., when the CU size is 8x4, 4x8, or the CU is coded in sbTMVP mode). In this case, the weighting factors {1 / 4, 1 / 8} are P N , and the weighting factors {3 / 4, 7 / 8} are P C can be used. P generated based on the motion vectors of vertically (horizontally) neighboring sub-blocks N About, P N Pixels in the same row (column) of P are weighted by the same factor. C can be added to. Local Illumination Compensation (LIC) LIC is an inter-prediction technique that models the local illumination change between the current block and the predicted block as a function of the change between the current block template and the reference block template. The parameters of this function can be expressed as a scaling factor α and an offset β that form a linear equation: α*p[x]+β, which compensates for the illumination change, where p[x] is the reference sample pointed to by the MV at position x in the reference picture. If wrap-around motion compensation is enabled, the MV can be clipped considering the wrap-around offset. Since α and β can be derived based on the current block template and the reference block template, no signaling overhead is required for them other than signaling the LIC flag to indicate the use of LIC in AMVP mode. LIC can be used in inter CUs with the following aspects: - Intra-neighbor samples can be used in LIC parameter derivation. - LIC may be disabled in blocks with fewer than 32 luma samples. - For both non-sub-block and affine modes, LIC parameter derivation can be performed based on template block samples corresponding to the current CU instead of partial template block samples corresponding to the first upper left 16x16 unit. - Samples of a reference block template can be generated using block MV and MC without rounding them to integer-pel resolution (or precision). For bi-prediction inter-CUs, two sets of LIC parameters can be derived separately for L0 and L1 prediction samples. An iterative method can be applied to derive the L0 and L1 LIC parameters. Specifically, the L0 LIC parameters can first be derived by minimizing the difference between the L0 template prediction T0 and the template T, and the samples of T can be updated by subtracting the corresponding samples of T0. Then, the L1 parameters can be computed to minimize the difference between the L1 template prediction T1 and the updated template. Finally, the L0 parameters can be re-tuned in the same manner. According to the present disclosure, when bi-prediction is applied to the current block, prediction samples can be derived based on a weighted average. Previously, bi-prediction signals (i.e., bi-prediction samples) could be derived through a simple average of an L0 prediction signal (L0 prediction samples) and an L1 prediction signal (L1 prediction samples). That is, bi-prediction samples were derived as the average of L0 prediction samples based on an L0 reference picture and MVL0 and L1 prediction samples based on an L1 reference picture and MVL1. However, according to the present disclosure, when bi-prediction is applied, bi-prediction signals (bi-prediction samples) can be derived through a weighted average of an L0 prediction signal and an L1 prediction signal, as in the following equation 7. [Formula 7] In weighted average pair prediction, there are five weights may be allowed. For each pairwise predicted CU, the weight w may be determined in one of two ways: 1) For non-merge CUs, the weight index can be signaled after motion vector difference. 2) For merge CU, the weight index can be inferred from surrounding blocks based on the merge candidate index. Weighted average biprediction can only be applied to CUs with 256 or more luma samples (i.e., CU width x CU height is 256 or more). For low-delay pictures, all five weights can be used, and for non-low-delay pictures, three weights ( ) can only be used. In encoders, fast search algorithms can be applied to find weight indices without significantly increasing encoder complexity. These algorithms can be summarized as follows: - When combined with AMVR, unequal weights for 1-pel and 4-pel motion vector precision can be identified conditionally if the current picture is a low-latency picture. - When combined with affine, affine ME (Motion Estimation) is performed for unequal weights only if the affine mode is currently selected as the best mode. - In paired prediction, if two reference pictures are identical, unequal weights are only checked conditionally. - If certain conditions are satisfied based on the POC distance between the current picture and reference pictures, coding QP, and temporal level, unequal weights are not searched. The BCW weight index is coded using one context-coded bin and a bypass-coded bin. The first context-coded bin indicates whether equal weights are used. If unequal weights are used, additional bins are signaled by the bypass to indicate which unequal weights are used. Weighted Prediction (WP) is a coding tool for efficiently encoding video content in the presence of fading. WP allows weighting parameters (weights and offsets) to be signaled for each reference picture in reference picture lists L0 and L1. During motion compensation, the weights and offsets of the corresponding reference pictures can be applied. WP and BCW can be designed for different types of video content. To avoid interactions between WP and BCW, which complicate decoder design, when a CU uses WP, the BCW weight index is not signaled, and w can be inferred as 4 (i.e., equal weighting is applied). For merge CUs, weight indices can be inferred from surrounding blocks based on merge candidate indices. This approach is applicable to both the standard merge mode and the inherited affine merge mode. For the constructed affine merge mode, affine motion information can be constructed based on motion information from up to three blocks. The process of deriving a CU's BCW index using the constructed affine merge mode is as follows. 1) Divide the range of BCW indices {0,1,2,3,4} into three groups: {0}, {1,2,3}, and {4}. If the BCW indices of all control points belong to the same group, the BCW index is derived according to step 2), otherwise, the BCW index is set to 2. 2) If two or more control points have the same BCW index, this BCW index value is assigned to the candidate, otherwise the BCW index of the currently configured candidate is set to 2. Bi-Directional Optical Flow (BDOF) Bi-directional Optical Flow (BDOF) can be used to improve bi-prediction signals. For example, BDOF can be applied at the 4x4 subblock level and to CUs that satisfy the following conditions: - If the height of the CU is not 4 and the size of the CU is not 4x8 - If the CU is not coded using affine mode or ATMVP merge mode. - If the CU is coded using the "true" bi-prediction mode (i.e., one of the two reference pictures is earlier than the current picture in display order and the other is later than the current picture). BDOF can be applied to only the luma component, only the chroma component, or both the luma and chroma components. BDOF mode is based on the concept of optical flow, which assumes smooth object motion. For each 4x4 sub-block, motion enhancement (v) is achieved by minimizing the difference between L0 and L1 prediction samples. x ,v y) can be calculated. Then, the motion enhancement can be used to adjust the biprediction sample values ​​of the 4x4 sub-block. The following steps can be applied to the BDOF process. First, the horizontal and vertical gradients of the two prediction samples and (k=0,1) can be obtained by directly calculating the difference between two surrounding samples according to Equations 8 and 9 below. [Formula 8] [Formula 9] Here, I (k) (i,j) represents the sample value at the coordinate (i,j) of the predicted signal in the list k (k=0,1), and shift1 can be calculated based on the luma bit depth bitDepth as shift1=max(6,bitDepth-6). And, the auto- and cross-correlation of gradients, S1, S2, S3, S5, and S6 can be calculated as shown in Equation 10 below. [Formula 10] Here, can be calculated as shown in Equation 11 below. [Formula 11] Ω represents a 6x6 window around a 4x4 subblock. Improved movement (v x ,v y ) can be derived using the following equation 12. [Formula 12] Here, and, is the floor function. Based on the motion enhancement and gradient, an adjustment according to the following [Equation 13] can be computed for each sample of a 4x4 sub-block. [Formula 13] Finally, the BDOF samples of the CU can be computed by adjusting the pairwise prediction samples as in Equation 14 below. [Formula 14] From above, n a , n b and n s2 The values ​​are 3, 6, and 12, respectively. These values ​​are selected so that the multiplier in the BDOF process does not exceed 15 bits, and the maximum bit width of the intermediate parameters of the BDOF process is maintained within 32 bits. To derive the gradient values, the predicted samples I of the list k (k=0,1) that are outside the boundary of the current CU (k) (i,j) must be generated. Figure 23 shows the extended CU region used in BDOF. Referring to Figure 23, BDOF uses a single row / column extended around the CU boundary. To control the computational complexity of generating prediction samples outside the boundary, a bilinear filter is used to generate prediction samples in the extended region, and a normal 8-tap motion compensation interpolation filter is used to generate prediction samples within the CU. These extended sample values ​​are only used for gradient computation. For the remaining steps of the BDOF process, if any samples and gradient values ​​are needed outside the CU boundary, they are padded (i.e., repeated) from their nearest neighbors. If the width and / or height of a CU is greater than 16 luma samples, it may be split into subblocks having the same width and / or height as 16 luma samples, and the boundaries of the subblocks may be treated as CU boundaries in the BDOF process. The maximum unit size for the BDOF process is limited to 16x16. If BCW is allowed for the current block, i.e., if the BCW weight indices indicate unequal weights, BDOF is not allowed. Similarly, if WP is allowed for the current block, i.e., if the luma_weight_lx_flag is 1 for one of the two reference pictures, BDOF is also not allowed. BDOF is also not allowed if the CU is coded in symmetric MVD mode. Hereinafter, the multi-hypothesis prediction (MHP) mode will be described in detail. As described above, the multi-hypothesis prediction mode refers to a method of using an additional prediction block (or predictor) to a base prediction block. The multi-hypothesis prediction mode can be selectively used as one of the various inter prediction modes described above. It should be understood that the multi-hypothesis prediction mode according to the embodiments of the present disclosure is not limited to these names. In the present specification, the multi-hypothesis prediction mode may also be referred to as a multi-reference mode, a multi-reference prediction, a multi-reference prediction mode, a multi-prediction block mode, an MHP mode, a multi-hypothesis inter-prediction mode, an inter-inter combined prediction mode, a combined inter-prediction mode, a combined prediction mode, a multi-inter prediction mode, a multi-prediction mode, an additional reference prediction mode, an additional reference mode, a multi-prediction block, etc. FIG. 24 is a diagram illustrating an example of a method for performing prediction by a decoding device according to an embodiment of the present disclosure, and FIG. 25 is a diagram illustrating examples of prediction blocks used in a multi-prediction block mode according to an embodiment of the present disclosure. While the example illustrates that prediction is performed by a decoding device (300), the same prediction may also be performed by an encoding device (200). Referring to FIG. 24, the decoding device may perform inter prediction to generate a base prediction block (S900). If additional prediction blocks are generated in addition to the prediction blocks generated by unidirectional prediction or bidirectional prediction in general inter prediction, this may correspond to a multi-prediction block mode. When the multi-prediction block mode is applied, additional motion information and weight information may be signaled / derived in addition to motion information in each direction during the inter prediction process. For example, the decoding device may generate (or derive) additional prediction blocks in addition to the prediction blocks generated (or derived) by unidirectional prediction or bidirectional prediction, and combine them with each other. To distinguish from additional prediction blocks, a prediction block generated (or derived) by unidirectional prediction or bidirectional prediction supported in general inter prediction is called a regular prediction block, and a prediction block additionally generated (or derived) according to a multi-prediction block mode is called an additional prediction block. In addition, in the present disclosure, a prediction block generated (or derived) by basic inter prediction and a prediction block generated (or derived) by additional prediction may be referred to as a reference block in order to distinguish them from the final prediction block, or the terms prediction block and reference block may be used interchangeably. In the embodiments described below, they are mainly referred to as a basic prediction block and an additional prediction block, but if they are included in the scope of the basic prediction block or additional prediction block defined and described in the present disclosure, even blocks referred to by other terms such as a reference block should be regarded as corresponding to the basic prediction block or additional prediction block in the present disclosure. In other words, regardless of the name, if a block is generated by the method described in the present disclosure and used according to the description of the present disclosure, it can be included in the scope of the prediction block or reference block in the present disclosure. Additionally, in the present disclosure, multiple prediction blocks or multiple reference blocks may mean additional prediction blocks, and in some cases, may be used to mean both additional prediction blocks and base prediction blocks. Additionally, in the present disclosure, deriving and generating a reference block or prediction block may be used interchangeably. That is, the description of deriving a reference block or prediction block may mean generating a reference block or prediction block, and the description of generating a reference block or prediction block may mean deriving a reference block or prediction block. As an example, a base prediction block may include an L0 prediction block and / or an L1 prediction block. As described above, a base prediction block may also be referred to as a base reference block, or may also be referred to as an initial prediction block, an initial reference block, a temporary prediction block, a temporary reference block, a reference prediction block, a regular prediction block, a regular reference block, etc. Additionally, as an example, a base prediction block may mean an L0 prediction block or an L1 prediction block, or may mean a block obtained by weighting L0 and L1 prediction blocks. As a specific example, the decoding device can derive a first base prediction block and a second base prediction block of the current block by performing bidirectional prediction, and can use the first base prediction block and the second base prediction block to combine with an additional prediction block by weighting them. Alternatively, the decoding device can generate a base prediction block of the current block by performing unidirectional prediction. In other words, the base prediction block can mean each of a plurality of prediction blocks generated through bidirectional prediction, can mean a result of weighting these prediction blocks, or can mean a prediction block generated through unidirectional prediction. In one embodiment, weights may be used for the weighted sum of L0 and L1 prediction blocks. Here, the weights may be collectively referred to as Bi-prediction with CU-based Weights (BCW) and CU-based Weights (CW). The weights may be derived from a weight candidate list. The weight candidate list may include multiple weight candidates and may be predefined in the encoding / decoding device. The weight candidates may be a set of weights (i.e., a first weight and a second weight) representing weights applied to each of the bidirectional prediction blocks, or may be weights applied to prediction blocks in either direction. If only the weights applied to a prediction block in one direction are derived from the weight candidate list, the weights applied to the prediction block in the other direction may be derived based on the weights derived from the weight candidate list. For example, the weights applied to the prediction block in the other direction may be derived by subtracting the weights derived from the weight candidate list from a predetermined value. In one embodiment, a weight index indicating weights used for weighted prediction of a current block may be derived within a weight candidate list. In the present disclosure, the weight index may be referred to as bcw_idx or a bcw index. The weight index may be derived by a decoding device or signaled by an encoding device. If derived by a decoding device, the weight index may be derived as a weight index of a specific merge candidate within a merge candidate list. For example, a specific merge candidate may be specified within the merge candidate list by a merge index. The decoding device can generate an additional prediction block based on the multi-prediction block mode (S910), and generate a final prediction block by combining the base prediction block and the additional prediction block (S920). In one embodiment, when the multi-prediction block mode is applied, the decoding device may derive additional prediction blocks up to a predefined number and combine the derived additional prediction blocks with the base prediction block. In other words, the decoding device may combine additional prediction blocks less than or equal to the predefined number with the base prediction block. In addition, as an example of a method of combining the base prediction block and the additional prediction blocks, a weighted sum may be applied. As an example, the predefined number may be 2. Or, as an example, the predefined number may be one of 1, 2, 3, and 4. Here, the predefined number may be referred to as the maximum number of the multi-prediction block mode. The number of additional prediction blocks described above is merely an example applicable to the present disclosure, and various numbers of additional prediction blocks may be applied to the multi-prediction block mode according to the present disclosure. As shown in the example of Fig. 25, bidirectional prediction is applied as the basic prediction, so that a first basic prediction block (P0) and a second basic prediction block (P1) are generated, and two additional prediction blocks (P2, P3) can be generated. In the example, a case where two prediction blocks are generated for each prediction direction is shown, but of course, the number of prediction blocks for each prediction direction can vary. When multiple additional prediction blocks (P2, P3) are combined, the multiple additional prediction blocks (P2, P3) can be sequentially weighted-combined with the base prediction block (P'). For example, when up to two additional prediction blocks are generated, the base prediction block and the first additional prediction block (P2) can be weighted-combined to generate a prediction block, and the generated prediction block and the second additional prediction block (P3) can be weighted-combined to generate a final prediction block (P). The prediction block generated by weighting the base prediction block and the first additional prediction block (P2) can be referred to as an intermediate prediction block. This process can be expressed by Equation 15 below. [Formula 15] Step 1: P' = (P0 + P1) / 2 Step 2: P'' = w0 * P2 + (1-w0) * P' Step 3: P = w1 * P3 + (1-w1) * P'' Here, w0 represents the weight of the first additional prediction block, and w1 represents the weight of the second additional prediction block. In addition, P' may represent a basic prediction block obtained by weighting the first basic prediction block and the second basic prediction block, and P" may represent an intermediate prediction block. In the present example, the same weight (0.5) is given to the first basic prediction block (P0) and the second basic prediction block (P1), but it is to be understood that different weights may be given. In the present disclosure, the basic prediction block may represent a weighted sum of the first basic prediction block and the second basic prediction block, may represent either the first basic prediction block or the second basic prediction block, or may represent both the first basic prediction block and the second basic prediction block. When unidirectional prediction is performed to generate the basic prediction block, the basic prediction block may represent a single prediction block generated by the unidirectional prediction. Alternatively, when multiple additional prediction blocks are combined, the base prediction block and the multiple additional prediction blocks may be weighted together. That is, after multiple additional prediction blocks are generated, weights may be applied to each of the multiple additional prediction blocks and the base prediction block (or the first base prediction block and the second base prediction block) and weighted together. Meanwhile, although not illustrated in FIG. 24, as described above, in order to perform decoding in the decoding device (300), a bitstream may be received from the encoding device (200) and image information may be obtained from the received bitstream. Accordingly, information regarding a basic prediction mode may be obtained from the bitstream to generate a basic prediction block (S900), and information regarding an additional prediction mode may be obtained from the bitstream to generate an additional prediction block (S910). In addition, weight information applied to the basic prediction block and the additional prediction block may be obtained from the bitstream to generate a final prediction block (S920). Additionally, the decoding device (300) can determine whether to apply the multi-prediction block mode. In this case, a step for determining whether to apply the multi-prediction block mode may be added prior to step S910. Whether to apply the multi-prediction block mode may be explicitly signaled and transmitted, or may be implicitly derived (or determined) by the decoding device. For example, whether a multi-prediction block mode is applied can be signaled and encoded by an encoding device and transmitted to a decoding device. Specifically, information indicating whether a multi-prediction block mode is applied (hereinafter referred to as “multi-prediction block mode information”), for example, a multi-prediction block mode flag, can be signaled by an encoding device and transmitted to a decoding device. At this time, a condition for signaling / parsing the multi-prediction block mode flag can be predefined. The signaling / parsing condition of the multi-prediction block mode flag can be an allowance condition of the multi-prediction block mode. If the signaling / parsing condition of the multi-prediction block mode flag is satisfied, the decoding device can parse the multi-prediction block mode flag from the bitstream. Alternatively, as another example, whether to apply the multi-prediction block mode can be induced by the decoding device based on predefined encoding information. As an example, whether to apply the multi-prediction block mode can be defined in the same way as the multi-prediction block mode permission condition (or signaling / parsing condition) described below. For example, multi-prediction block mode information can be represented as a syntax element such as mhp_flag, and whether multi-prediction block mode is applied, i.e., whether additional prediction blocks exist, can be signaled / derived through the value of mhp_flag. If the value of mhp_flag is 0, it can indicate that multi-prediction block mode is not applied or that additional prediction blocks do not exist, and if the value of mhp_flag is 1, it can indicate that multi-prediction block mode is applied or that additional prediction blocks exist. For example, if the maximum number of additional prediction blocks (MaxNum) is 2, the value of mhp_flag can indicate the presence of additional prediction blocks in the manner shown in Table 9 below. [Table 9] When a multi-prediction block mode is applied to the current block, the decoding device may obtain information regarding the additional prediction mode (hereinafter referred to as “additional prediction mode information”) to generate an additional prediction block. For example, the additional prediction mode information may include prediction information and / or weight information. Based on the prediction information, an additional prediction block according to the multi-prediction block mode may be generated, and based on the weight information, the additional prediction block may be combined with the base prediction block (or intermediate prediction block). Specifically, the prediction information may include information indicating a prediction mode applied to the generation of an additional prediction block (hereinafter referred to as prediction mode information), information indicating a detailed prediction mode required to generate an additional prediction block according to the prediction mode (hereinafter referred to as detailed prediction mode information), and various other information required to generate an additional prediction block by applying the prediction mode and the detailed prediction mode. The weight information may indicate a weight used to combine the additional prediction block with the base prediction block. In conventional multi-prediction block modes, the prediction mode applied to the generation of additional prediction blocks is limited to the inter-prediction mode. In the present disclosure, encoding / decoding efficiency can be improved by including intra-prediction and / or IBC prediction in the prediction mode applied to the generation of additional prediction blocks. For example, the additional prediction mode may include at least one of inter mode, intra mode, or IBC mode. Furthermore, the inter mode may include merge mode and MVP mode (or AMVP) mode. The prediction mode information may include information indicating whether the additional prediction mode is inter mode, intra mode, or IBC mode. Furthermore, the prediction mode information may include information indicating whether the additional prediction mode is merge mode or MVP mode among the inter modes. For example, the prediction mode information may be represented by a syntax element indicating whether one of the aforementioned additional prediction modes is applied. As an example, the prediction mode information may include a merge flag indicating whether the merge mode is applied as the additional prediction mode, or an intra flag indicating whether the intra mode is applied. Alternatively, a predefined prediction mode may be used to generate the additional prediction block. Alternatively, the additional prediction mode may be selected based on predefined encoding information. For example, when the merge mode is used to generate an additional prediction block, the prediction information may include a merge index. The merge index may indicate a specific merge candidate within a merge candidate list. When the AMVP mode is used to derive an additional prediction block, the prediction information may include a motion vector predictor index, a reference index, and motion vector difference information. The motion vector predictor index may indicate a specific candidate within the motion vector predictor candidate list. As described above, the additional prediction mode information may include weight information. The weight information may indicate the weights used when combining the additional prediction block with the base prediction block. If there are multiple additional prediction blocks, weight information for each of the multiple additional prediction blocks may be included in the prediction information. For example, the weight information may be indicated by a weight index. The additional prediction mode used to derive the additional prediction block and the basic prediction mode used to derive the base prediction block can be distinguished from each other. For example, the MVP candidate list for generating the base prediction block and the MVP candidate list for generating the additional prediction block can be independently constructed. Furthermore, the merge candidate list for generating the base prediction block and the merge candidate list for generating the additional prediction block can also be independently constructed. However, depending on the embodiment, it is also possible to use the same candidate list but use an index indicating a different candidate, or to derive another candidate list from one candidate list. Additionally, information for a base prediction block and information for multiple prediction blocks can be distinguished from each other. For example, when the value of the multi-prediction block mode flag (mhp_flag), which indicates whether a multi-prediction block mode is applied, is 1, the merge flag, which indicates whether the merge mode or the inter mode is used to generate an additional prediction block, can be represented as mhp_mrg or mhp_mrg_flag. In other words, the syntax element indicating information about the additional prediction mode and the syntax element indicating information about the base prediction mode can be distinguished from each other. All syntax names described in this disclosure are merely examples, and all such names are subject to change. Even if the syntax names differ from those described in this disclosure, if the syntax includes or represents the information described in this disclosure, it is included within the scope of the syntax of this disclosure. In addition, in the embodiments described below, for the convenience of explanation, the inter mode used as an additional prediction mode may be referred to as MHP-INTER, MHP-inter mode, MHP-inter prediction mode, or MHP-inter prediction, etc., and the intra mode used as an additional prediction mode may be referred to as MHP-INTRA, MHP-intra mode, MHP-intra prediction mode, or MHP-intra prediction, etc. In addition, the IBC mode used as an additional prediction mode may be referred to as MHP-IBC, MHP-IBC mode, MHP-IBC prediction mode, or MHP-IBC prediction, etc. In addition, the merge mode used as an additional prediction mode may be referred to as MHP-merge mode, etc., and the AMVP mode used as an additional prediction mode may be referred to as MHP-AMVP mode, etc. Additionally, information indicating whether the MHP-inter prediction mode is applied among the aforementioned prediction mode information may be referred to as MHP-inter information, and as an example, the MHP-inter information may include an MHP-inter flag (mhp_inter_flag). Additionally, information indicating whether the MHP-intra prediction mode is applied may be referred to as MHP-intra information, and as an example, the MHP-intra information may include an MHP-intra flag (mhp_intra_flag). Additionally, information indicating whether the MHP-merge mode is applied may be referred to as MHP-merge information, and as an example, the MHP-merge information may include an MHP-merge flag (mhp_mrg_flag or mhp_mrg). Meanwhile, in embodiments according to the present disclosure, signaling information or a signal may correspond to generating the information or a signal, or may include generating the information or a signal. Signaling the information or a signal may be performed by an encoding device, and the encoding device may encode the signaled or generated information or a signal. Alternatively, signaling information or a signal may be used in the same sense as encoding, or may be used in the sense of including both the operations of generating and encoding the information or a signal. Additionally, in embodiments according to the present disclosure, parsing information or signals may correspond to or include obtaining the information or signals from a bitstream. Parsing the information or signals may be performed by a decoding device, and the decoding device may parse the information or signals and restore a block or picture based on the parsed information or signals. Example 1 According to one embodiment, when a multi-prediction block mode is applied, MHP-intra information indicating whether an intra prediction mode is applied to the generation of additional prediction blocks may be signaled / parsed. In the embodiments described below, the case where the MHP-intra flag (mhp_intra_flag) is used as the MHP-intra information will be described as an example. FIG. 26 is a flowchart showing an operation of obtaining additional prediction mode information in a decoding method performed by a decoding device according to one embodiment. The decoding device (300) can receive the bitstream generated by the encoding device (200) and obtain additional prediction mode information from the received bitstream. As described above, the additional prediction mode information can include prediction information and weight information, and the prediction information can include information about the prediction mode used to generate the additional prediction block (prediction mode information) and motion information. Referring to FIG. 26, when the maximum number of additional prediction blocks that can be generated is MaxNum, the decoding device can perform the multi-prediction block mode by repeating all or part of the process illustrated in FIG. 26 MaxNum times. That is, the loop can be repeated as many times as the maximum number of additional prediction blocks (until the result of S1100 becomes No). A decoding device can parse a multi-prediction block mode flag (mhp_flag) from a bitstream (S1110). The multi-prediction block mode flag (mhp_flag) can indicate whether an additional prediction block exists. For example, when the value of the multi-prediction block mode flag (mhp_flag) is 1, it can indicate that an additional prediction block exists. When the value of the multi-prediction block mode flag (mhp_flag) is not 1, for example, when it is 0, it can indicate that an additional prediction block does not exist. If the value of the multi-prediction block mode flag (mhp_flag) is 1 (example of S1120), MHP-intra information indicating whether intra prediction is used in generating an additional prediction block is parsed (S1130). In the present embodiment, before determining whether merge mode or AMVP is applied in generating an additional prediction block, it may first be determined whether intra prediction is applied. For example, the MHP-intra information may include an MHP-intra flag (mhp_intra_flag). When the value of the MHP-intra flag (mhp_intra_flag) is 1, it may indicate that intra prediction is applied in generating an additional prediction block. If the value of the MHP-intra flag (mhp_intra_flag) is not 1, for example, 0, it may indicate that intra prediction is not applied in generating an additional prediction block. If the value of the MHP-Intra flag (mhp_intra_flag) is 1 (example of S1140), additional information used for intra prediction can be parsed (S1150). A detailed explanation of this will be provided later. If the value of the MHP-Intra flag (mhp_intra_flag) is not 1 (NO in S1140), MHP-merge information indicating whether the merge mode is used to generate the additional prediction block is parsed (S1160). Alternatively, the MHP-merge information may include an MHP-merge flag such as mhp_mrg or mhp_mrg_flag. When the value of the MHP-merge flag is 1, it may indicate that the merge mode is applied to the generation of the additional prediction block. If the value of the MHP-merge flag is not 1, for example, 0, it may indicate that the merge mode is not applied to the generation of the additional prediction block. When the value of the MHP-merge flag (mhp_mrg) is 1 (example of S1170), additional information used in the merge mode, such as the merge index (merge_idx) and weight information (weight_idx), can be obtained by parsing (S1180). If the value of the MHP-Merge flag is not 1 (NO in S1170), additional information used in AMVP can be obtained by parsing (S1190). For example, the reference index (refIdx), motion vector predictor index (mvp_idx), motion vector difference information (mvd_data), and weight information (weight_idx) can be obtained by parsing. Although the decoding method is described in FIG. 26, the same operation can be applied to the encoding method performed by the encoding device. The encoding device (200) can generate and encode information regarding a multi-prediction block mode. The encoded information regarding the multi-prediction block mode can be output in the form of a bitstream and transmitted to the decoding device (300). Specifically, the encoding device (200) can generate information indicating whether a multi-prediction block mode is applied to the current block, and generate information regarding a basic prediction mode used to generate a basic prediction block based on whether a multi-prediction block mode is applied, and information regarding an additional prediction mode used to generate an additional prediction block. The generated information can be encoded and output in the form of a bitstream. For example, information indicating the presence of an additional prediction block (e.g., multi-prediction block mode flag (mhp_flag)), MHP-intra information indicating whether intra prediction is used to generate the additional prediction block (e.g., mhp_intra_flag), and information indicating whether merge mode is used to generate the additional prediction block (e.g., mhp_mrg or mhp_mrg_flag) can be generated or signaled and encoded. Additionally, when intra prediction is used to generate additional prediction blocks, additional information required for intra prediction can be generated or signaled and encoded. Additionally, when merge mode is used to generate additional prediction blocks, additional information required for applying merge mode (e.g., merge index, etc.) can be generated or signaled and encoded. Additionally, when an inter prediction mode, for example, AMVP mode, is used to generate additional prediction blocks, additional information required for applying the AMVP mode (e.g., reference index, motion vector predictor index, motion vector differential information, etc.) can be generated or signaled and encoded. Additionally, weighting information used to combine additional prediction blocks with the base prediction block or to combine between multiple additional prediction blocks can be generated, signaled, and encoded. As in the present embodiment, combining the inter mode, which finds the block most similar to the current block in the reference picture, with the intra mode, which is derived from adjacent samples of the current block, not only increases compression efficiency but also has the effect of removing discontinuity between the current block and adjacent samples. Meanwhile, when signaling / parsing MHP-Intra information, which indicates whether intra prediction is applied to the generation of additional prediction blocks, it is also possible to signal / parse this information only when certain conditions are met. This reduces signaling / parsing overhead and reduces complexity in both encoding and decoding devices. The relevant details are described below. FIG. 27 is a flowchart showing another example of an operation for obtaining additional prediction mode information in a decoding method performed by a decoding device according to one embodiment. Referring to FIG. 27, if the value of the multi-prediction block mode flag (mhp_flag) is 1 (example of S1120), the decoding device (300) can determine whether a predetermined condition is satisfied (S1200). If the predetermined condition is satisfied (example of S1200), the MHP-intra flag can be parsed according to the above-described content to determine whether MHP-intra prediction is applied, and the remaining operations can be performed (S1130 to S1190). If the set condition is not satisfied (No in S1200), the MHP-merge information can be parsed to determine whether the MHP-merge mode is applied without determining whether the MHP-intra prediction is applied (S1160). Below, we describe in detail the conditions established to determine whether to signal / parse MHP-Intra information: - The given condition may be related to the default prediction mode of the current block. The given condition may be satisfied if the default prediction mode does not include a specific prediction mode. For example, MHP-Intra prediction may not be applied when the default prediction mode is at least one of the AMVP mode, CIIP mode, and GPM mode. In other words, if the default prediction mode is at least one of the aforementioned modes, the given condition is not satisfied, and MHP-Intra information may not be signaled / parsed. That is, in this case, intra prediction may not be used to generate or derive additional prediction blocks. - The given condition may be whether refinement is applied to the current block. Here, the refinement applied to the current block may refer to a tool or technique, such as DMVR, which improves motion information, or BDOF, which improves sample values ​​within the block. For example, if refinement is applied to the current block based on techniques such as DMVR or BDOF, MHP-Intra prediction may not be applied. In other words, if refinement is applied to the current block, the given condition is not satisfied, and MHP-Intra information may not be signaled / parsed. In other words, in this case, intra prediction may not be used to generate or derive additional predicted blocks. - The given condition may be related to the size of the block. For example, the condition may be determined based on the block size or the block width / height ratio. Specifically, when the block size (width x height) is smaller than the given size, the given condition may be satisfied and MHP-Intra prediction may be allowed. For example, when the block size is smaller than 1024, MHP-Intra prediction may be allowed. In other words, if the current block size is smaller than the given size, MHP-Intra information may be signaled / parsed, and if it is larger than the given size, MHP-Intra information may not be signaled / parsed. - The given condition may be related to the Quantization Parameter (QP). For example, when the quantization parameter is less than a threshold, the given condition may be satisfied and MHP-Intra prediction may be allowed. For example, the threshold may be set to a value greater than 32, so that MHP-Intra prediction may be allowed when the quantization parameter is 32. In other words, when the quantization parameter is less than the threshold, MHP-Intra information may be signaled / parsed, and when it is greater than the threshold, MHP-Intra information may not be signaled / parsed. - The given condition may be related to the temporal layer. For example, MHP-Intra prediction may be allowed when the temporal layer index is less than a threshold. For example, the threshold may be set to a value greater than 4, so that MHP-Intra prediction may be allowed when the temporal layer index is 4. In other words, MHP-Intra information may be signaled / parsed when the temporal layer index is less than the threshold, and MHP-Intra information may not be signaled / parsed when the temporal layer index is greater than the threshold. The conditions described above are merely examples applicable to one embodiment, and other conditions may also apply. Furthermore, one of the conditions described above may apply, or two or more conditions may apply together. Although the decoding method is described in FIG. 27, the same operation can be applied to the encoding method performed by the encoding device (200). Therefore, in addition to the operation or encoding method of the encoding device (200) described above with respect to FIG. 26, MHP-Intra information can be signaled when the above-described conditions are satisfied. When decoding or encoding according to the above description, the prediction modes used to generate additional prediction blocks can be combined as shown in Table 10 below. The combinations below were derived assuming MaxNum of 2 and 3, respectively. Below, "INTRA" is used to indicate MHP-Intra prediction, and "INTER" is used to indicate either MHP-Inter prediction or MHP-Merge mode. [Table 10] In one embodiment, the number of additional prediction blocks generated by intra prediction may also be included as a condition for determining whether to signal / parse MHP-intra information. For example, only one additional prediction block may be allowed to be generated by intra prediction. In the embodiments described below, for convenience of explanation, the additional prediction block to which intra prediction is applied will be referred to as an intra additional prediction block, an MHP-intra block, or an MHP-intra prediction block. FIG. 28 is a flowchart illustrating another example of an operation for obtaining additional prediction mode information in a decoding method performed by a decoding device according to one embodiment. In the example of FIG. 28, the number of intra additional prediction blocks can be determined as a condition for determining whether to signal / parse MHP-intra information. Referring to Fig. 28, as an example of determining the aforementioned set condition (S1200), the number of intra additional prediction blocks can be determined (S1210), and as an example, the number of intra additional prediction blocks can be limited to 1. Accordingly, if the number of currently generated intra additional prediction blocks is 0 (example of S1210), this corresponds to a case where the set condition is satisfied, and MHP-Intra information can be parsed to determine whether MHP-Intra prediction is applied, and other remaining operations can be performed (S1130 to S1190). If the number of currently generated intra additional prediction blocks is not 0 (NO in S1210), that is, if one intra additional prediction block has already been generated, whether to apply MHP-intra prediction is not determined, but MHP-merge information is parsed to determine whether to apply MHP-merge mode (S1160), and the remaining operations can be performed (S1170 to S1190). Although the decoding method is described in Fig. 28, the same operation can be applied to the encoding method performed by the encoding device (200). Therefore, in the operation or encoding method of the encoding device (200) described above with reference to Figs. 26 and 27, the number of intra additional prediction blocks can be determined as a predetermined condition, and MHP-intra information can be generated or signaled only when the number of intra additional prediction blocks is less than the predetermined number. Referring back to the above [Table 10], when MaxNum is 2 and the combination of {INTER, INTER} is used, the MHP-Intra flag is signaled / parsed twice even though the intra mode is not applied to the generation of additional prediction blocks. Also, when MaxNum is 3 and the combination of {INTER, INTER, INTER} is used, the MHP-Intra flag is signaled / parsed three times even though the intra mode is not applied to the generation of additional prediction blocks. However, limiting the number of intra-additional prediction blocks to one reduces signaling / parsing overhead and enables efficient encoding / decoding. In this case, the prediction modes used to generate the additional prediction blocks can be combined as described in Table 11 below. [Table 11] In the above example, since only one intra additional prediction block is allowed, combinations containing two or more "INTRA"s are not allowed. Comparing [Table 11] with [Table 10] described above, when MaxNum is 2, the {INTRA, INTRA} combination does not occur. Also, when MaxNum is 3, the {INTRA, INTRA}, {INTRA, INTRA, INTER}, {INTRA, INTER, INTRA}, {INTER, INTRA, INTRA}, {INTRA, INTRA, INTRA} combinations do not occur. FIG. 29 is a flowchart illustrating another example of an operation for acquiring multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. In the example of FIG. 29, the number of additional prediction blocks identified in advance can be determined as a condition for determining whether to signal / parse MHP-intra information. Referring to FIG. 29, information indicating the number of additional prediction blocks can be parsed (S1221). To this end, the encoding device (200) can signal the number of additional prediction blocks applied to the current block and transmit it to the decoding device (300). For example, information indicating the number of additional prediction blocks can be signaled with a syntax such as mhp_num. When the value of mhp_num is '0', it indicates that there is no additional prediction block, when it is '10', it indicates that there may be one additional prediction block, and when it is '11', it indicates that there may be two additional prediction blocks. This binarization method is only an example of a method for signaling information indicating the number of additional prediction blocks. In addition, information indicating the number of additional prediction blocks can be signaled through various methods such as fixed length code, truncated rice, truncated binary, exponential-Golomb, etc., and the meaning of mhp_num can be expanded and applied as the number of additional prediction blocks allowed increases. For example, MHP-Intra information can only be parsed when the number of additional prediction blocks is 1. Therefore, if the number of additional prediction blocks is greater than 0 (example of S1222), it is determined whether the number of additional prediction blocks is 1 (S1223). Although the flowchart of Fig. 29 is limited to the case where merge mode is applied to the current block, this is merely an example, and it is obvious that other conditions among the various conditions described above may be applied. If the number of additional prediction blocks is 1 (yes in S1223), the MHP-Intra flag can be parsed (S1130). If the number of additional prediction blocks is not 1, i.e., greater than 1 (no in S1123), the MHP-Merge flag can be parsed (S1160). The operations after parsing each flag are as described above. Although the decoding method is described in FIG. 29, the same operation can be applied to the encoding method performed by the encoding device (200). Accordingly, in the operation or encoding method of the encoding device (200) described above with reference to FIGS. 26 and 28, the number of additional prediction blocks applied to the current block can be signaled. The method for signaling the number of additional prediction blocks is the same as that described above with respect to the decoding method of FIG. 29. Additionally, the encoding method can signal MHP-Intra information only when the number of additional prediction blocks is a certain number. For example, the MHP-Intra flag can be signaled only when the number of additional prediction blocks is 1. Referring back to [Table 11] above, if the first additional prediction block is not an intra additional prediction block, the MHP-Intra information is signaled / parsed until an intra additional prediction block is generated. In particular, for the combinations of {INTER, INTER} and {INTER, INTER, INTER}, the MHP-Intra information is signaled / parsed twice and three times even though there is no intra additional prediction block. However, allowing MHP-Intra prediction only when the number of additional prediction blocks is a certain number (e.g., 1) reduces signaling / parsing overhead and enables efficient encoding / decoding. In this case, the prediction modes used to generate the additional prediction blocks can be combined as described in Table 12 below. [Table 12] In the above example, MHP-Intra prediction is allowed only when there is one additional prediction block, so the only possible combination containing "INTRA" is {INTRA}. In the aforementioned embodiments, MHP-Intra information was signaled / parsed prior to MHP-Merge information. However, the order can be changed, taking into account the applicability of the prediction mode. For example, it is possible to determine whether MHP-Merge mode is applicable by giving priority to the signaling / parsing of MHP-Merge information prior to MHP-Intra information. Fig. 30 is a flowchart illustrating another example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. In the example of Fig. 30, MHP-merge information is parsed prior to MHP-intra information. Referring to Fig. 30, the operations of determining the current number of times to loop as many times as MaxNum (S1300), parsing the multi-prediction block mode flag (S1310), and determining its value (S1320) are the same as those described above. If the value of the multi-prediction block mode flag (mhp_flag) is 1 (example of S1320), the MHP-merge information is parsed first before the MHP-intra information (S1330). If the value of the MHP-merge flag (mhp_mrg), which is an example of the MHP-merge information, is 1, it indicates that the merge mode is used to generate the additional prediction block, and if the value of the MHP-merge flag (mhp_mrg) is 0, it indicates that the merge mode is not used to generate the additional prediction block. If the MHP-merge information indicates that the MHP-merge mode is applied, that is, if the value of the MHP-merge flag (mhp_mrg) is 1 (example of S1340), information required to apply the MHP-merge mode, such as merge index (merge_idx) and weight information (weight_idx), can be parsed (S1350). If the MHP-merge information indicates that the MHP-merge mode is not applied, i.e., if the value of the MHP-merge flag (mhp_mrg) is 0 (No in S1340), the MHP-intra information, for example, the MHP-intra flag (mhp_intra_flag), can be parsed (S1370). However, in this case, depending on the embodiment, it may first be determined whether a set condition is satisfied (S1360), and if the set condition is satisfied (Yes in S1360), the MHP-intra information may be parsed. Here, the description of the set condition is as described above. If the MHP-Intra information indicates that the MHP-Intra mode is applied, i.e., if the value of the MHP-Intra flag (mhp_intra_flag) is 1 (example of S1380), additional information required for applying the MHP-Intra mode is parsed (S1390). If the MHP-Intra information indicates that the MHP-Intra mode is not applied, that is, if the value of the MHP-Intra flag (mhp_intra_flag) is 0 (No in S1380), it is determined that the MHP-AMVP is applied, and information required for applying the MHP-AMVP, such as the reference index (refIdx), the motion vector predictor index (mvp_idx), the motion vector difference information (mvd_data), and the weight index (weight_idx), can be parsed (S1400). Although the decoding method is described in Fig. 30, the same operation can be applied to the encoding method performed by the encoding device. The encoding device (200) can generate and encode information indicating the presence or absence of an additional prediction block (e.g., multi-prediction block mode flag (mhp_flag)), and generate and encode MHP-merge information when an additional prediction block exists. When the MHP-merge mode is applied, additional information required for applying the MHP-merge mode (e.g., merge index, weight index, etc.) can be generated and encoded. When MHP-Merge mode is not applied, MHP-Intra information is generated and encoded depending on whether the specified conditions are satisfied, and when MHP-Intra mode is applied, additional information required for applying MHP-Intra mode can be generated and encoded. When MHP-Intra mode is not applied, additional information required for applying MHP-Inter mode (e.g., reference index, motion vector predictor index, motion vector difference information, etc.) can be generated and encoded. Assuming that the MHP-Merge mode is more applicable, signaling / parsing MHP-Merge information with priority over MHP-Intra information, as in the example described above, can reduce unnecessary signaling / parsing, thereby reducing signaling / parsing overhead and implementing efficient encoding / decoding. FIG. 31 is a flowchart illustrating another example of an operation for obtaining multi-prediction block mode information in a decoding method performed by a decoding device according to one embodiment. In this example, the application of MHP-merge mode and MHP-intra mode can be distinguished using MHP-merge information without separately signaling / parsing MHP-intra information. Referring to Fig. 31, the operations of determining the current number of times to loop as many times as MaxNum (S1500), parsing the multi-prediction block mode flag (S1510), and determining its value (S1520) are the same as those described above. If the value of the multi-prediction block mode flag is 1 (example of S1520), MHP-merge information, for example, the MHP-merge flag (mhp_mrg), is parsed (S1530). In this example, if the value of the MHP-merge flag is 1, it may indicate that the merge mode is applied to the generation of the additional prediction block, and if the value of the MHP-merge flag is 0, it may indicate that the intra mode is applied to the generation of the additional prediction block. Therefore, if the value of the MHP-merge flag (mhp_mrg) is 1 (example of S1540), additional information (e.g., merge index, weight index, etc.) required to apply the MHP-merge mode can be parsed (S1550). If the value of the MHP-Merge Flag (mhp_mrg) is 0 (S154No), this corresponds to the case where the MHP-Intra mode is applied. Therefore, additional information required to apply the MHP-Intra mode can be parsed (S1560). Meanwhile, according to another example, it is also possible to determine whether MHP-Merge mode is applicable only when certain conditions are met. In this case, at least one of the conditions described above with reference to Figure 27 can be applied, and if the condition is met, the MHP-Merge information can be parsed. Additionally, it is possible to parse additional information necessary to apply the MHP-Intra mode only when certain conditions are met. In this case, if the MHP-Merge flag value is 0 or the certain conditions are not met, additional predicted blocks may not be generated. Although the decoding method is described in Fig. 31, the same operation can be applied to the encoding method performed by the encoding device. The encoding device (200) can generate and encode information indicating whether an additional prediction block exists (e.g., multi-prediction block mode flag (mhp_flag)), and can generate and encode MHP-merge information if an additional prediction block exists. If the MHP-merge mode is applied, additional information required for applying the MHP-merge mode (e.g., merge index, weight index, etc.) can be generated and encoded. If the MHP-merge mode is not applied, additional information required for applying the MHP-intra mode can be generated and encoded. Additionally, as previously described, it is also possible to generate and encode MHP-merge information only when certain conditions are satisfied. In this case, at least one of the conditions described above with reference to Figure 27 may be applied, and MHP-merge information may be generated and encoded when the condition is satisfied. Additionally, it is possible to generate and encode additional information necessary to apply the MHP-Intra mode only when certain conditions are met. In this case, if the MHP-Merge flag value is 0 or the certain conditions are not met, additional predicted blocks may not be generated. According to the example, since it is possible to determine whether the MHP-Intra mode is applied using the MHP-Merge information without separately signaling / parsing the MHP-Intra information, signaling / parsing overhead can be reduced and efficient encoding / decoding can be implemented. Meanwhile, the aforementioned embodiment can be equally applied to the MHP-IBC prediction mode. Accordingly, at least one of the MHP-Intra prediction mode or the MHP-IBC prediction mode can be included in the additional prediction mode for generating an additional prediction block, and information regarding the MHP-IBC prediction mode can also be signaled / parsed in the additional prediction mode in the same manner as described above. Example 2 According to the present embodiment, in addition to signaling related information as described above, the multi-prediction block mode can also be inherited or derived from surrounding blocks. Hereinafter, embodiments related to this will be described in detail. Merge mode is a mode that directly borrows motion information from adjacent or non-adjacent neighboring blocks without signaling motion information. Borrowing motion information from neighboring blocks can be expressed as inheritance, transfer, or derivation. However, the scope of the disclosed embodiments is not limited by these terms, and even if referred to by terms other than inheritance, transfer, or derivation, if it substantially corresponds to the operation, function, or meaning described in the embodiment, it may be included within the scope of the embodiment. According to one embodiment, when a multi-prediction block mode is applied to adjacent or non-adjacent neighboring blocks of a current block, it is possible to derive information about the multi-prediction block mode in a manner identical to or similar to other information. Here, the information about the multi-prediction block mode may include information indicating whether the multi-prediction block mode is applied (multi-prediction block mode information), information about the basic prediction mode, information about the additional prediction mode, etc. Specifically, when a merge mode is applied to a current block, prediction information can be derived from neighboring blocks. The prediction information can include motion information of the neighboring blocks. When a multi-prediction block mode is applied to a neighboring block for obtaining motion information, the prediction information can include information about the multi-prediction block mode of the neighboring block. In this case, information about the multi-prediction block mode of the neighboring block can be inherited and used to generate an additional prediction block of the current block. In other words, the multi-prediction block mode can also be applied to the current block. Here, the neighboring blocks can include both adjacent blocks and non-adjacent blocks, and can include temporal neighboring blocks and spatial neighboring blocks. Whether the inheritance method described in the present embodiment is applicable can be signaled and derived in units of a picture parameter set (PPS), a sequence parameter set (SPS), a picture header (PH), a slice header (SH), a coding tree unit (CTU), or a coding unit (CU). A flag for determining whether to apply inherited multiple prediction blocks can be distinguished from a flag (mhp_flag) for determining whether to signal multiple prediction blocks, and when the value of the flag is 1, the inheritance method described below can be applied. In addition, even if the value of the flag is 1, if a predetermined condition is not satisfied, the inheritance method described below may not be applied. In addition, even if the flag does not exist, if a predetermined condition is not satisfied, the inheritance method described below may not be applied. Additionally, it is also possible to apply both signaling and induction methods to obtain information about multiple prediction block modes. For example, if N additional prediction blocks are included and there are M additional prediction blocks obtained through induction (or inheritance) (M<=N), information about NM additional prediction blocks can be obtained through signaling. The conditions for determining whether multiple prediction blocks are inherited can be set as follows: - When DMVR is applied to a block, inheritance of multi-prediction blocks may not be applied. Furthermore, whether inheritance is applied may vary depending on the prediction mode of the multi-prediction block. For example, inheritance may not be applied to MHP-Intra mode. - When a block is subject to BDOF, inheritance of multi-prediction blocks may not be applied. Furthermore, whether inheritance is applied may vary depending on the prediction mode of the multi-prediction block. For example, inheritance may not be applied in MHP-Intra mode. - When LIC is applied to a block, inheritance of multi-prediction blocks may not be applied. Furthermore, whether inheritance is applied may vary depending on the prediction mode of the multi-prediction block. For example, inheritance may not be applied to MHP-Intra mode. - When OBMC is applied to a block, inheritance of multi-prediction blocks may not be applied. Furthermore, whether inheritance is applied may vary depending on the prediction mode of the multi-prediction block. For example, inheritance may not be applied to the MHP-Intra mode. - When CIIP, GPM, or GPM-INTRA are applied to a block, inheritance of multi-prediction blocks may not be applied. Furthermore, whether inheritance is applied may vary depending on the prediction mode of the multi-prediction block. For example, inheritance may not be applied to MHP-Intra mode. Multi-prediction block mode combines various modes or types of methods to predict the current block, improving encoding / decoding quality and efficiency. By applying conditions based on the examples described above, selectively inheriting multiple prediction blocks can be achieved. However, if the combined effect of inheritance is negligible or insignificant, inheritance can be disallowed, reducing decoder complexity and enabling efficient decoding. In addition, when the multi-prediction block mode applied to the surrounding block includes an intra mode, i.e., when the multi-prediction block for the surrounding block includes an intra additional prediction block, whether to inherit the intra mode (MHP-intra mode) or the intra additional prediction block can be determined according to the conditions set as follows: - The MHP-Intra mode applied to the surrounding blocks may not be inherited. Specifically, if the surrounding blocks included in the merge candidate list are encoded / decoded using the multi-prediction block mode and the MHP-Intra mode is applied, the MHP-Intra mode may be excluded and inherited in the process of deriving the motion information of the current block. Fig. 32 illustrates an example of inheriting the MHP-Intra mode from a surrounding block to which the multi-prediction block mode is applied. Since the prediction modes illustrated in Fig. 32 are all used for additional prediction blocks, even if they are indicated as INTRA and INTER, they may actually mean MHP-Intra and MHP-Inter. Fig. 32 (A) illustrates a case where there are surrounding blocks encoded / decoded using three additional prediction blocks, and the intra mode, inter mode, and inter mode are used to generate the three additional prediction blocks, respectively. In this case, when inheriting the multi-prediction block mode of the surrounding blocks, the intra mode may be excluded and inherited. If three additional prediction blocks are allowed for the current block, information about the prediction mode applied to the remaining one additional prediction block can be obtained through signaling. In this case, the prediction mode obtained through signaling can be both intra mode and inter mode, and the aforementioned embodiment can be applied to the signaling method. FIG. 32(B) illustrates a case where there are neighboring blocks encoded / decoded using two additional prediction blocks, and both inter mode is used to generate the two additional prediction blocks. In this case, both inter modes can be inherited. If three additional prediction blocks are allowed for the current block, information about the prediction mode applied to the remaining one additional prediction block can be obtained through signaling. In this case, the prediction mode obtained through signaling can be both intra mode and inter mode, and the aforementioned embodiment can be applied to the signaling method.Figure 32 (C) illustrates a case where there is a neighboring block encoded / decoded using one additional prediction block, and an intra mode is used to generate one additional prediction block. In this case, if three additional prediction blocks are allowed for the current block without inheriting the intra mode from the neighboring block, information about the prediction modes applied to the three additional prediction blocks can all be obtained through signaling. In this case, the prediction mode obtained through signaling can be either an intra mode or an inter mode, and the aforementioned embodiment can be applied to the signaling method. That is, according to the example of Figure 32, the intra mode can be applied to the generation of the additional prediction block only through signaling, not through inheritance. It's also possible to inherit without distinguishing between intra and inter modes. This method is computationally efficient because it always inherits without judging conditions during the inheritance process. Furthermore, since intra modes can be applied to multiple additional prediction blocks, it can be effectively used in sequences where compression ratios can be improved through the weighted sum of multiple intra prediction blocks. - The number of inherited intra modes can be limited. Since there can be a signaled intra mode and an inherited intra mode, there may be more than one intra mode applied to an additional prediction block. In this case, it is possible to limit the number of inherited intra modes. Fig. 33 illustrates an example in which the number of intra modes inherited from a neighboring block to which a multiple prediction block mode is applied is limited to 1. Fig. 33 (A) illustrates a case in which a neighboring block encoded / decoded using three additional prediction blocks exists, and an intra mode, an intra mode, and an inter mode are used to generate the three additional prediction blocks, respectively. In this case, when inheriting the multiple prediction block mode information of the neighboring block, the remaining intra modes and inter modes except for the first intra mode can be inherited. If three additional prediction blocks are allowed for the current block, information about the prediction mode applied to the remaining one additional prediction block can be obtained through signaling. For example, the prediction mode obtained through signaling can be both intra mode and inter mode, and the above-described embodiment can be applied to the signaling method. FIG. 33 (B) also shows a case where there are neighboring blocks encoded / decoded using three additional prediction blocks, and intra mode, intra mode, and inter mode are used to generate the three additional prediction blocks, respectively. As another example, when inheriting the multiple prediction block mode information of the neighboring blocks, it is also possible to inherit the remaining intra modes and inter modes except for the last intra mode. FIG. 33 shows a case where there are neighboring blocks encoded / decoded using additional prediction blocks, and intra mode, intra mode, and inter mode are used to generate the three additional prediction blocks, respectively. FIG. 33 is only an example applicable to one embodiment. The number and order of intra modes that are allowed to be inherited can be modified differently from the above-described examples. Meanwhile, it is also possible to limit information related to multiple prediction block modes inherited from neighboring blocks to information that distinguishes the intra, inter, and merge modes applied to additional prediction blocks. Information related to multiple prediction block modes can include motion information, weighting information, and other additional information in addition to prediction mode information. However, since storing a large amount of information directly impacts the increased capacity of internal memory, a change that limits the amount of information stored is possible. For example, the storage of information about the MHP-Intra mode can be restricted. That is, while prediction mode information for distinguishing the MHP-Intra mode can be included in the inherited information, information about a specific detailed prediction mode may not be included in the inherited information. In this case, a preset default mode can be used as the detailed prediction mode, or a detailed prediction mode derived from neighboring blocks can be used. Furthermore, if weight information is not included in the inherited information, the default weight value can be used, or weight information derived from neighboring blocks can be used. Furthermore, even if additional information about the MHP-Intra mode exists, it is possible to not include it in the inherited information, but to use the default value or derive it from neighboring blocks. As another example, the storage of information for MHP-Inter mode and MHP-Merge mode can be restricted. That is, prediction mode information and motion information for distinguishing between MHP-Inter mode and MHP-Merge mode can be included in the inherited information, but weight information may not be included in the inherited information. In this case, preset default weight values ​​or weight information derived from neighboring blocks can be used. Furthermore, even when additional information exists for MHP-Inter mode and MHP-Merge mode, it is possible to use default values ​​or derive them from neighboring blocks without including them in the inherited information. Meanwhile, the aforementioned embodiment can be equally applied to the MHP-IBC prediction mode. Accordingly, at least one of the MHP-Intra prediction mode or the MHP-IBC prediction mode can be included in the additional prediction mode for generating additional prediction blocks, and whether the MHP-IBC prediction mode is inherited can also be determined in the same manner as described above. Example 3 According to an embodiment of the present disclosure, when an intra mode is included in an additional prediction mode, it is also possible to derive the relevant information at the decoder stage without signaling it. FIG. 34 is a flowchart showing an example of a decoding method performed by a decoding device according to one embodiment, in which information on an MHP-intra mode is derived at a decoder stage. Here, numMHP can represent the number of additional prediction blocks that are signaled or inherited. In this example, information about the MHP-Intra mode is not signaled or inherited, so numMHP can represent the sum of the MHP-Inter mode and the MHP-Merge mode. In other words, numMHP can represent the sum of the number of additional prediction blocks to which the MHP-Inter mode is applied and the number of additional prediction blocks to which the MHP-Merge mode is applied. Additionally, it is possible to limit numMHP to the number of additional prediction blocks being signaled. Referring to FIG. 34, a basic prediction block is generated during the decoding process (S1600), and when numMHP is greater than 0 (example of S1610), an inter additional prediction block (MHP-inter block) can be generated in the corresponding number (S1620). If the specified conditions are satisfied (e.g., S1630), an intra-additional prediction block (MHP-intra block) can be generated by applying the MHP-intra mode (S1640). Furthermore, the base prediction block, the inter-additional prediction block generated through signaling and inheritance, and the intra-additional prediction block generated through a derivation method according to an embodiment can be combined according to a specified rule to generate a final prediction block (S1650). For example, the base prediction block and the additional prediction block can be weighted and combined to generate the final prediction block. The above-described method can be extended and applied to MHP-IBC mode or MHP-Inter mode. When numMHP is greater than 0, additional prediction blocks can be generated according to MHP-IBC mode or MHP-Intra mode, and MHP-Inter mode and MHP-IBC mode can be derived when a predetermined condition is satisfied. If numMHP is defined to mean the number of MHP-Inter modes, the derived mode can be one or more of the three modes according to the predefined allowable number for each mode. The same method can be applied when numMHP means the number of MHP-Intra mode or MHP-IBC mode. FIG. 35 is a flowchart showing another example of a decoding method performed by a decoding device according to one embodiment, in which information for an MHP-intra mode is derived at a decoder stage. Referring to FIG. 35, a base prediction block is generated during the decoding process (S1700), and when numMHP is greater than 0 (example of S1710), a corresponding number of inter additional prediction blocks (MHP-inter blocks) can be generated (S1720). numMHP can indicate the number of signaled or inherited additional prediction blocks. In this example, information about the MHP-intra mode is not signaled or inherited, so numMHP can indicate the sum of the MHP-inter mode and the MHP-merge mode. In addition, it is also possible to limit numMHP to the number of signaled additional prediction blocks. When no additional prediction block exists, i.e., numMHP is 0 (NO in S1710), and a predefined condition is satisfied (YES in S1730), an intra additional prediction block (MHP-Intra block) can be generated (S1740). That is, even if no additional prediction block signaled or inherited for the current block exists, an additional prediction block can be generated by applying the MHP-Intra mode if the predefined condition is satisfied. In addition, a final prediction block can be generated by combining a base prediction block and an inter additional prediction block generated through signaling and inheritance (a block generated in step S1720) or an intra additional prediction block generated through a derivation method according to an embodiment (a block generated in step S1740) according to a set rule (S1650). For example, a final prediction block can be generated by weighting the base prediction block and the additional prediction block. The above-described method can be extended and applied to MHP-IBC mode or MHP-Inter mode. Even if numMHP == 0, additional prediction blocks can be generated according to MHP-IBC mode or MHP-Inter mode if a certain condition is satisfied. If numMHP is defined to mean the number of MHP-Inter modes, the derived mode can be one or more of the three modes depending on the predefined allowable number for each mode. The same method can be applied when numMHP means the number of MHP-Intra mode or MHP-IBC mode. The examples of FIGS. 34 and 35 described above may be combined with each other. Specifically, when numMHP > 0 and a given condition is satisfied, an MHP-Intra block may be generated, and when numMHP == 0 and another given condition is satisfied, an MHP-Intra block may also be generated. Combining prediction blocks of the inter mode, which finds the block most similar to the current block in the reference picture, and the intra mode, which is derived from adjacent samples of the current block, not only increases compression efficiency but also has the effect of eliminating discontinuity between the current block and adjacent samples. Therefore, the similarity with adjacent samples can be considered as a condition for determining whether to apply the MHP-Intra mode (the "predetermined condition" described above). Therefore, in the above-described embodiment, the condition for determining whether to derive the MHP-Intra can be defined as follows. Figure 36 is a diagram for explaining the error between adjacent samples of the current block and adjacent samples of the base prediction block. Referring to Figure 36, the adjacent samples (cA, cL) of the current block and the adjacent samples (p) of the regular prediction block A , p L ) error (S) A , S L), an intra additional prediction block can be generated by applying the MHP-Intra mode. That is, the discontinuity of a block can be determined based on the error between adjacent samples of the current block and the predicted block. In the example, the error may be information indicating a difference or error between certain pieces of information. In some cases, cost may also be used with a similar meaning. Specifically, the upper adjacent sample c of the current block A and the upper adjacent sample p of the base prediction block A S is a liver error A It is possible to compare the left adjacent sample c of the current block with the threshold. L and the left adjacent sample p of the base prediction block L S is a liver error L can also be compared with a threshold value. Furthermore, comparisons can be made by considering both the upper adjacent sample and the left adjacent sample. For convenience of explanation, the upper left is not described, but the sample at that location can be considered when calculating the inter-sample error using the upper, left, or upper / left samples. The threshold value can be set according to Equations 16 and 17 below. [Formula 16] threshold = width * template height / λ [Formula 17] template width * height / λ Here, λ can be set to a value that satisfies λ≥1. Specifically, the error (S) between each sample (or sample value, hereinafter sample and sample value are considered to have the same meaning) A, S L ) or the cost can be obtained by the following methods or a combination thereof: - Error or cost can be calculated by considering SAD (Sum of Absolute Difference). That is, it can be calculated as in Equation 18 below. In Equation 18, c and p represent adjacent samples of the current block and the base prediction block, respectively, and x represents the location of the adjacent sample. In addition, it can be applied to N samples included in the area included in the upper side, left side, or upper / left side. [Formula 18] - Error or cost can be calculated by considering MR-SAD (Mean Reduced-Sum of Absolute Difference). That is, it can be calculated as shown in Equation 19 below. In Equation 19, c and p represent adjacent samples of the current block and the base prediction block, respectively, and x represents the location of the adjacent sample. In addition, it can be applied to N samples included in the area included in the upper side, left side, or upper / left side. [Formula 19] - The error or cost can be calculated by considering the sum squared error (SSE) between samples. That is, it can be calculated as shown in Equation 20 below. In Equation 20, c and p represent adjacent samples of the current block and the base prediction block, respectively, and x represents the location of the adjacent sample. In addition, it can be applied to N samples included in the area included in the upper side, left side, or upper / left side. [Formula 20] - The error or cost can be calculated by considering the mean squared error (MSE) between samples. That is, it can be calculated as shown in Equation 21 below. In Equation 21, c and p represent adjacent samples of the current block and the base prediction block, respectively, and x represents the location of the adjacent sample. In addition, it can be applied to N samples included in the area included in the upper side, left side, or upper / left side. [Formula 21] The cost calculation method for each block can be determined variably depending on the characteristics of the block. For example, a block with LIC applied may calculate its cost considering MR-SAD. Another example is a block with BCW applied may calculate its cost considering MR-SAD. Another example is a block with DMVR and BDOF applied may calculate its cost considering SAD. The adjacent sample area may consider the upper and left 1-pixel lines closest to the current block, or multiple upper and left pixel lines. The size of the sample area may be fixed according to a predefined rule between the encoder and decoder, or may be determined variably according to separate signaling or conditions. Conditions for determining the size of the sample area may include sample distribution, block size information, and detailed prediction mode. The established conditions used to determine whether to apply the MHP-Intra mode may consider the sample distribution of the region adjacent to the current block and the sample distribution of the region adjacent to the predicted block. Specifically, the upper adjacent sample c of the current block A and the upper adjacent sample p of the base prediction block A We can consider the distribution of the left adjacent sample c of the current block. L and the left adjacent sample p of the base prediction block LThe inter-distribution can be considered. Furthermore, both the upper adjacent sample and the left adjacent sample can be considered and compared. For convenience of explanation, the upper left is not described, but the sample at that location can be considered when calculating the inter-sample error using the upper, left, or upper / left samples. The distribution of each sample adjacent to the current block and the base prediction block can be considered in terms of variance and standard deviation, and if the difference in the distribution of each block is greater than a threshold, the MHP-Intra mode can be allowed. Additionally, the given conditions may include block size information. That is, the block size (width x height), the block width and height, and the block ratio (width / height or height / width) may be included as conditions. For example, if the block size is less than 32, the MHP-Intra mode may not be applied. Alternatively, if the block size is greater than 1024, the MHP-Intra mode may not be applied. In another example, the MHP-Intra mode may not be applied when the width or height is less than 8 or greater than 64. Alternatively, the following restrictions may be applied depending on the block ratio: - if(width >= height && width / height > 4 ) MHP-INTRA is not allowed - else if(width < height && height / width > 4) MHP-INTRA is not allowed In addition, the given condition may include the detailed prediction mode of the block. That is, whether to apply the MHP-Intra mode may be determined based on the detailed prediction mode used to generate the basic prediction block of the current block. For example, the merge mode includes various detailed prediction modes such as subblock merge, MMVD, CIIP, GPM, and GPM-INTRA in addition to the basic merge (regular merge). In particular, since CIIP and GPM-INTRA already include intra information in the prediction block, the MHP-Intra mode may not be additionally applied when the corresponding prediction method is applied to the basic prediction block. In addition, the MHP-Intra mode may not be applied in the AMVP mode, which has high motion accuracy due to MVD. In addition, the MHP-Intra mode may not be applied in the block to which motion information refinement or prediction sample refinement is applied, such as DMVR and BDOF. In the present embodiment, the application of the MHP-Intra mode may mean that the MHP-Intra mode is induced in the decoding device. In addition, the given condition may include the number of numMHP. It can be determined whether to induce the MHP-Intra mode depending on the number of signaled or inherited MHP-AMVP, MHP-merge mode, or MHP-Intra mode. For example, when numMHP is the number of signaled and inherited MHP-AVMP / MHP-merge modes, the induced MHP-Intra mode may be allowed when numMHP is 0. In another example, the induced MHP-Intra mode may be allowed when numMHP is greater than 0 and less than MaxNum. The induced MHP-Intra mode may be used in combination with the signaled MHP-Intra mode and the inherited MHP-Intra mode. Meanwhile, the aforementioned embodiment can be equally applied to the MHP-IBC prediction mode. Accordingly, at least one of the MHP-Intra prediction mode or the MHP-IBC prediction mode can be included in the additional prediction mode for generating additional prediction blocks, and information regarding the MHP-IBC prediction mode can also be derived in the same manner as described above. Example 4 The present embodiment relates to a method for signaling or deriving information required to generate an intra additional prediction block when the MHP-intra mode is applied, i.e., when the intra mode is used to generate an additional prediction block to generate an intra additional prediction block. Information required to apply the MHP-Intra mode can be signaled / parsed when the value of the MHP-Intra flag (mhp_intra_flag) is 1, and the intra additional prediction block can be generated using the information. In the present disclosure, in order to distinguish between the prediction mode used as a term indicating the MHP-Inter mode (or MHP-Merge mode, MHP-AMVP) and the MHP-Intra mode, the detailed mode, prediction technique, prediction tool, prediction method, etc. applied to each prediction mode are all referred to as the detailed prediction mode. However, the scope of the disclosed embodiments is not limited to these terms, and even if referred to by other terms, if it has substantially the same meaning as the detailed prediction mode in the present disclosure, it can be included in the scope of the disclosed embodiments. Specifically, the detailed prediction mode used to generate the intra additional prediction block can be determined within a specific list, which may be a Most Probable Mode (MPM) list. Among the multiple candidates within the MPM list, a candidate indicated by an index can be used as the detailed prediction mode, and the index can be defined using a syntax element such as mhp_mpm_idx. Figure 37 is a flowchart illustrating an example of an operation for signaling / parsing information regarding MHP-Intra mode. Referring to FIG. 37, an MHP-intra flag (mhp_intra_flag) indicating whether the intra mode is applied to the generation of an additional prediction block, i.e., whether the MHP-intra mode is applied, is signaled / parsed (S1800), and in the case where the MHP intra mode is applied (example of S1810), information indicating a detailed prediction mode used in the MHP intra mode among multiple candidates existing in the MPM list (e.g., mhp_mpm_idx) can be signaled / parsed (S1820). For convenience of explanation, the flowchart only shows the signaling / parsing of the MHP mpm index, but it is of course possible to additionally signal / parse other information required to perform the MHP intra mode. Alternatively, the prediction method applied to the MHP intra mode may be determined as one of the other candidates not included in the MPM list. Figure 38 is a flowchart illustrating another example of the operation of signaling / parsing information regarding the MHP intra mode. Referring to FIG. 38, an MHP-intra flag (mhp_intra_flag) indicating whether intra mode is applied to the generation of an additional prediction block, i.e., whether MHP-intra mode is applied, is signaled / parsed (S1900). When the MHP-Intra mode is applied, i.e., when the value of the MHP-Intra flag is 1 (example of S1910), a flag (mhp_mpm_flag) indicating whether the detailed prediction mode applied to the MHP-Intra mode exists in the MPM list can be signaled / parsed (S1920). If the value of mhp_mpm_flag is 1, it indicates that the detailed prediction mode applied to the MHP-Intra mode exists in the MPM list, and if the value of mhp_mpm_flag is 0, it indicates that the detailed prediction mode applied to the MHP-Intra mode does not exist in the MPM list. If the detailed prediction mode applied to the MHP-Intra mode exists in the MPM list, i.e., if the value of mhp_mpm_flag is 1 (example of S1930), information (mhp_mpm_idx) pointing to a specific candidate in the MPM list can be signaled / parsed (S1940). If the prediction method applied to the MHP intra mode does not exist in the MPM list, i.e., if the value of mhp_mpm_flag is 0 (NO in S1930), information indicating one of the other candidates not belonging to the MPM list can be signaled / parsed. For example, the information can be signaled / parsed as a syntax element such as mhp_mpm_remainder (S1950). The MPM list for the MHP-Intra mode can be configured as a separate list and a separate detailed prediction mode, distinct from the MPM list for the basic Intra mode (i.e., the Intra mode used to generate the basic prediction block). Alternatively, the same MPM list can be used for both the MHP Intra mode and the basic Intra mode to reduce encoding / decoding complexity. Meanwhile, it is also possible to enhance the compression effect by signaling / parsing the detailed prediction mode with the highest selection rate among the prediction mode candidates, prioritizing it over information (e.g., mhp_mpm_idx) indicating a specific candidate within the MPM list. Figure 39 is a flowchart illustrating another example of the operation of signaling / parsing information regarding the MHP intra mode. Referring to FIG. 39, an MHP-intra flag (mhp_intra_flag) indicating whether the intra mode is applied to the generation of an additional prediction block, i.e., whether the MHP-intra mode is applied, is signaled / parsed (S2000). When the MHP-Intra mode is applied, i.e., when the value of the MHP-Intra flag is 1 (example of S2010), a flag (mhp_mpm_flag) indicating whether the detailed prediction mode applied to the MHP-Intra mode exists in the MPM list can be signaled / parsed (S2020). If a detailed prediction mode applied to the MHP-Intra mode exists in the MPM list, i.e., if the value of mhp_mpm_flag is 1 (example of S2030), information indicating whether a detailed prediction mode with a high selectivity, for example, a planar mode, is used (e.g., mhp_not_planar_flag) is signaled / parsed with priority (S2040), so that whether a detailed prediction mode with a high selectivity is used can be preferentially determined. At this time, the MPM list can be configured for candidates excluding the planar mode. In this example, considering that the planar mode generally has a high selectivity for the basic prediction mode, whether to use the planar mode is preferentially determined. However, it is of course also possible to preferentially determine whether to use another detailed prediction mode considering the characteristics of the multi-prediction block mode. If the value of mhp_not_planar_flag is 1 (example of S2050), it indicates that planar mode is not used, so information (mhp_mpm_idx) pointing to a specific candidate in the MPM list can be signaled / parsed (S2060). If the detailed prediction mode applied to the MHP-Intra mode does not exist in the MPM list, i.e., if the value of mhp_mpm_flag is 0 (NO in S2030), information indicating one of the other candidates not belonging to the MPM list (e.g., mhp_mpm_remainder) can be signaled / parsed (S2080). If the value of mhp_not_planar_flag is not 1 (NO in S2050), it indicates that the planar mode is used, so additional prediction blocks can be generated using the planar mode (S2070). The MPM list for the MHP-Intra mode can consist of the following candidates, arranged in a predefined order. Furthermore, duplicate modes can be checked during the list construction process to ensure that no duplicate modes are included in the list: - Non-angular mode such as planar, DC, etc. - Angular mode with a specific value (angular mode or directional mode) - Angular mode with more fine / coarse segmentation - Prediction mode of adjacent / non-adjacent blocks encoded / decoded by intra mode or / and transformed mode (e.g., mode±1, mode±2, etc.) - History-based prediction mode that includes prediction information of intra blocks encoded / decoded before the current block. - Default mode (e.g., planner mode) - ISP mode - MIP mode - Intra prediction mode derived using DIMD - Intra prediction mode derived using TIMD method - Intra prediction mode stored (used) in the MHP (preceding block among multiple additional prediction blocks) of the current block or / and a transformed mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode stored in the multi-prediction block mode included in the adjacent / non-adjacent blocks encoded / decoded before the current block or / and a transformed mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode or / and a modified mode (e.g., mode±1, mode±2, etc.) when the prediction mode of the current block is CIIP mode - Intra prediction mode of adjacent / non-adjacent blocks encoded / decoded in CIIP mode or / and transformed mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode when the prediction mode of the current block is GPM-INTRA mode or / and a modified mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode of adjacent / non-adjacent blocks encoded / decoded in GPM-INTRA mode or / and transformed mode (e.g., mode±1, mode±2, etc.) The size of the MPM list can be determined by a value agreed upon between the encoder and decoder. For example, the size of the MPM list can be set to 6. Additionally, when constructing the MPM list and signaling mhp_mpm_idx, the candidate order of the MPM list can be changed to reduce signaling bits. For example, it can be based on template-based cost, and the candidate list can be constructed in descending order of cost. SAD, MR-SAD, SSE, MSE, etc. can be used to calculate the cost for reconstructing the candidate list. As a candidate detailed prediction mode, an angular mode can generate modes with a corresponding directional orientation by unequally partitioning the angles. The MHP-Intra mode can utilize these angular modes, and can be selected from a different set of angles than the base Intra mode by partitioning them more finely or more coarsely. For example, if the base Intra mode has 65 directional modes, the MHP-Intra mode can have a more finely partitioned 129 directional modes, or a more coarsely partitioned 35 directional modes. In another example, if the base Intra mode has 65 directional modes, it can target angles in other directions not supported by the base Intra mode. Figure 40 is a drawing showing an example of the locations of adjacent / non-adjacent blocks of the current block. The aforementioned adjacent blocks may refer to blocks at positions 1 to 5 of FIG. 40, and the non-adjacent blocks may refer to blocks at positions 6 to 23 of FIG. 40. MHP Intra mode can also use a fixed-value detailed prediction mode without signaling. The detailed prediction mode applied as a fixed value to MHP-Intra mode can be determined using the method below. Furthermore, it is also possible to determine a fixed-value detailed prediction mode by combining two or more of the methods below: - Planner mode or DC mode can be used as a detailed prediction mode for a fixed value. Specifically, the planner mode is selected when a reference sample exists, and the DC mode can be selected when a reference sample does not exist or the number of reference samples is less than a certain number. For example, the DC mode can be selected when the number of reference samples is 8. Alternatively, the number of reference samples can be determined by considering the width + height of the block. For example, when width >= height, it is less than height / 2, or when width < height, it is less than width / 2, the DC mode can be selected. - When scanning blocks in predefined adjacent / non-adjacent locations based on the current block, the mode of the first available block can be used as a fixed-value detailed prediction mode. At this time, the availability can be a location encoded / decoded in intra mode and existing within the allowed CTU range. The intra mode can include the SGPM mode. - Among the blocks in adjacent / non-adjacent locations defined in advance based on the current block, the detailed prediction mode with a high occurrence frequency of blocks encoded / decoded in intra mode can be used as a fixed value. If modes with the same occurrence frequency exist, the detailed prediction mode of the fixed value can be determined according to a predefined priority. - A history-based detailed prediction mode that includes prediction information for intra blocks encoded / decoded before the current block can be used as a fixed value. For example, the mode included in the 0th list of the history buffer can be a fixed-value detailed prediction mode. - The default mode can be determined as a fixed-value detailed prediction mode. This method can be used when the intra-detailed prediction mode cannot be obtained from adjacent / non-adjacent blocks and history-based storage buffers. In this case, the default detailed prediction mode can be set to planar mode. - ISP mode - MIP mode - INTRA prediction mode derived using DIMD - Intra prediction mode derived using TIMD method - Intra prediction mode stored (used) in the MHP (preceding block among multiple additional prediction blocks) of the current block or / and a transformed mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode stored in the multi-prediction block mode included in the adjacent / non-adjacent blocks encoded / decoded before the current block or / and a transformed mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode or / and a modified mode (e.g., mode±1, mode±2, etc.) when the prediction mode of the current block is CIIP mode - Intra prediction mode of adjacent / non-adjacent blocks encoded / decoded in CIIP mode or / and transformed mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode when the prediction mode of the current block is GPM-INTRA mode or / and a modified mode (e.g., mode±1, mode±2, etc.) - Intra prediction mode of adjacent / non-adjacent blocks encoded / decoded in GPM-INTRA mode or / and transformed mode (e.g., mode±1, mode±2, etc.) When there is more than one intra additional prediction block, a different fixed-value detailed prediction mode can be applied to each intra additional prediction block. For example, information about the fixed-value detailed prediction mode for the first intra additional prediction block is signaled, and information about the fixed-value detailed prediction mode applied to the next intra additional prediction block can be obtained using the derivation method described above. The method for determining the fixed-value detailed prediction mode for the first and second prediction blocks can be applied in a reversed order as described above, and both fixed-value detailed prediction modes can be obtained through signaling, or both can be obtained through the derivation method. Meanwhile, even if a single intra-additional prediction block exists, i.e., a single MHP-intra mode exists, it is also possible for two or more fixed-value detailed prediction modes to be used in that mode. For example, after generating each intra-prediction block using two or more fixed-value detailed prediction modes selected through the aforementioned derivation method, a weighted sum can be applied to generate a single intra-additional prediction block. Subsequently, the final prediction block is generated through a weighted sum with the base prediction block, as described above. Meanwhile, the aforementioned embodiment can be equally applied to the MHP-IBC prediction mode. Accordingly, at least one of the MHP-Intra prediction mode or the MHP-IBC prediction mode can be included in the additional prediction mode for generating the additional prediction block, and information regarding the MHP-IBC prediction mode can also be signaled / parsed or derived in the same manner as described above. Example 5 The present embodiment relates to a method for signaling or obtaining information (e.g., block vector information, weight information, etc.) necessary for generating a block when the IBC mode is applied as one of the additional prediction modes, i.e., when an MHP-IBC block is included in an additional prediction block. Figure 41 is a flowchart illustrating an example of the operation of signaling / parsing information required to generate an MHP-IBC block. Referring to FIG. 41, MHP-IBC information (e.g., mhp_ibc_flag) indicating whether the MHP-IBC mode is applied to the current block, i.e., whether the IBC mode is applied to the generation of an additional prediction block, can be signaled / parsed (S2100). If the value of mhp_ibc_flag is 1, it indicates that the MHP_IBC mode is applied. That is, it indicates that an MHP-IBC block exists. If the value of mhp_ibc_flag is not 1 (e.g., 0), it indicates that the MHP-IBC mode is not applied. The block vector information used to generate an MHP-IBC block can be derived using the merge method or the AMVP (ABVP) method. Therefore, if the value of mhp_ibc_flag is 1 (example of S2110), information indicating whether the block vector information used to generate an MHP_IBC block is obtained by the merge method (e.g., mhp_ibc_mrg) can be signaled / parsed (S2120). If the value of mhp_ibc_mrg is 1 (example of S2130), information indicating a specific candidate existing in the block vector candidate list (e.g., merge_idx) and weight information (e.g., weight_idx) can be signaled / parsed (S2140). If the value of mhp_ibc_mrg is 0 (No in S2130), information indicating a block vector predictor (e.g., bvp_idx) and information indicating a block vector differential value (e.g., bvd_data) can be signaled / parsed (S2150). Meanwhile, when there is more than one MHP-IBC prediction block, the block vectors of each prediction block may be different. In this case, the candidate lists of block vectors for each MHP-IBC prediction block may exist independently. Alternatively, different indices (e.g., merge_idx) may be used to indicate different block vectors within the same candidate list. Alternatively, a method may be applied in which the index (merge_idx) indicating the block vector for one block is signaled, and the index for another block is derived as merge_idx + 1 without signaling. The list of Block Vector Predictor (BVP) candidates can also be obtained from adjacent / non-adjacent neighboring blocks of the current block. The adjacent / non-adjacent neighboring blocks of the current block can represent the blocks at positions 1-5 and 6-23 in Figure 40 described above. The locations and check order of the neighboring blocks may be modified and applied accordingly. Example 6 The present embodiment relates to weight information required to generate a final prediction block using the prediction block when the MHP-Intra mode is applied, i.e., when the intra mode is used to generate an additional prediction block to generate an intra additional prediction block. As described above, weights may be applied to the base prediction block and the additional prediction block to generate the final prediction block. The present embodiment proposes a method for signaling and deriving such weight information. The method described in the present embodiment can be applied not only to the MHP-Intra mode but also to the MHP-IBC mode. The weight information applied to each additional prediction block can be obtained by signaling a weight index indicating one within the weight candidate list. When an MHP-Intra prediction block exists among the additional prediction blocks, the weight information applied thereto can be distinguished from the weight information applied to the MHP-Inter prediction block. In other words, the weight information applied to the MHP-Intra mode can be distinguished from the weight information applied to the MHP-Inter mode. Therefore, the weight candidate lists for the MHP-Inter mode and the weight candidate lists for the MHP-Intra mode can exist independently. In addition, the sizes of the weight candidate lists can also be defined as different values. Additionally, when an MHP-IBC prediction block exists among the additional prediction blocks, the weight information applied thereto can be distinguished from the weight information applied to the MHP-Intra prediction block and the MHP-Inter prediction block. In other words, the weight information applied to the MHP-IBC mode can be distinguished from the weight information applied to the MHP-Intra mode and the MHP-Inter mode. Accordingly, the weight candidate lists for the MHP-Inter mode and the MHP-Intra mode and the weight candidate list for the MHP-IBC mode can exist independently. These weights are values ​​defined for additional prediction blocks. For example, the weight applied to the additional prediction block can be defined as w, and the weight applied to the base prediction block can be defined as 1-w. Assuming that the weight w applied to the additional prediction block is 4 / 16, the weight 1-w applied to the base prediction block will have a value of 12 / 16. Figure 42 is a flowchart illustrating another example of the operation of signaling / parsing weight information for MHP-Intra mode. The method described in this example can be applied in combination with all or part of the methods described in the aforementioned embodiments. Therefore, previously explained terms and other details will not be repeated. Referring to FIG. 42, MHP-intra information (e.g., mhp_intra_flag) indicating whether MHP-intra mode is applied is signaled / parsed (S2200), and when MHP-intra information is applied, i.e., when the value of mhp_intra_flag is 1 (example of S2210), weight information (e.g., intra_weight_idx) applied to the MHP-intra mode or MHP-intra prediction block can be signaled / parsed (S2230). When intra_weight_idx, which is index information, is used as weight information, the final prediction block can be generated using the weight value indicated by the index. Meanwhile, when the MHP-IBC mode is applied, mhp_intra_flag and intra_weight_idx can be replaced with mhp_ibc_flag and ibc_weight_idx, respectively, and can be applied together with the motion information for the MHP-IBC mode. Additionally, the method described below can also be applied to MHP-IBC mode by appropriately replacing syntax elements. Figure 43 is a flowchart illustrating another example of the operation of signaling / parsing weight information for MHP-Intra mode. Referring to Figure 43, if a given condition is met (e.g., S2220), weight information can be signaled / parsed (S2230). If the given condition is not met (e.g., S2220), weight information set to default can be used without signaling. The conditions used to determine whether to signal / parse weight information can be determined by applying at least one of the following methods: - The above conditions can be determined based on information such as the current block size (width x height), the block width and height, and the block ratio (width / height or height / width). For example, if the block size is less than 32, the default weight information can be used. Alternatively, if the block size is greater than 1024, the default weight information can be used. - The above conditions can be determined according to the prediction mode of the current block. For example, if a prediction mode such as MMVD, GPM (GPM-INTRA), or CIIP is applied to the current block, default weight information can be used without signaling weight information. As another example, default weight information can be used when a subblock-based prediction mode is applied. In addition, default weight information can be used when the AMVP mode has high motion accuracy due to MVD. In addition, default weight information can be used when the block has improved motion information or improved prediction samples, such as DMVR and BDOF. - The above conditions can be determined based on the prediction direction of the current block. For example, whether intra_weight_idx is signaled can be determined depending on whether unidirectional prediction or bidirectional prediction is applied. For example, intra_weight_idx can be signaled when unidirectional prediction is applied, and default weight information can be used when bidirectional prediction is applied. - The above condition can be determined based on the BCW (Bi-prediction with CU-level Weight) index of the current block. For example, intra_wieght_idx can be signaled when the BCW index does not indicate a specific value (equal-weight). - The above conditions can be determined based on the LIC (Local Illumination Compensation) flag information of the current block. For example, if LIC is applied, intra_weight_idx can be signaled. - The above conditions can be determined based on the OBMC (Overlapped Block Motion Compensation) flag information of the current block. For example, when OBMC is applied, default weight information can be used. - The above conditions can be determined based on the number of additional prediction blocks. When multiple MHP-intra prediction blocks exist, intra_weight_idx can be signaled for only one block, and the weights for the remaining blocks can use default values. Alternatively, if MHP-inter prediction blocks exist, default weight information can be used. The aforementioned default weight information may be a predefined value. For example, the default weight value may be equal-weight. Alternatively, pixel-based weight information within a block may be defined as a default value. Figure 44 is a flowchart illustrating another example of the operation of signaling / parsing weight information for MHP-Intra mode. In the example of Fig. 44, weight information can be signaled / parsed differently depending on whether a given condition is satisfied. Specifically, if the given condition is satisfied (yes in S2220), the first weight information can be signaled / parsed (S2231), and if the given condition is not satisfied (no in S2220), the second weight information can be signaled / parsed (S2232). For example, the first weight information can be represented by a syntax element of intra_weight_idx0, and the second weight information can be represented by a syntax element of intra_weight_idx1. That is, the first weight information and the second weight information can be distinguished and applied according to conditions. The condition for distinguishing the first weight information and the second weight information can be at least one of the conditions described above. The weight candidate lists indicated by the first weight information and the weight candidate lists indicated by the second weight information can be independently constructed. Alternatively, the weight candidate lists indicated by the first and second weight information can be identical, and the first and second weight information can be adjusted to indicate different candidates. Candidates for weight information can be configured as follows. However, the candidates for weight information described below are merely examples applicable to one embodiment, and the values, order, number, etc. of the candidates can be changed. Table 13 below provides an example of expressing weight information using four indices. Intra_weight_idx0 and intra_weight_idx1 can have different weight values ​​within different ranges. When signaling a single weight index, the intra_weight_idx value in Table 13 can be referenced. [Table 13] Alternatively, it is possible to configure weight information as shown in Table 14 below. In the example in Table 14, weight information is expressed using two indices. You can see that it is composed of candidates that have different weight values ​​based on the region within the block and candidates that have the same weight value for all regions within the block. intra_weight_idx0 (intra_weight_idx) shows an example of dividing a block into four and applying different weights to each region. When signaling a single weight index, you can refer to the intra_weight_idx value in Table 14. [Table 14] Figure 45 is a diagram showing an example of dividing a current block and applying different weights to each divided area when applying weights to an MHP-intra prediction block. Referring to Figure 45, the current block can be divided into two or three vertically, horizontally, or diagonally, and both equal and unequal divisions are possible. Furthermore, it can be divided into a different number of regions, i.e., four or more, and equal / unequal divisions and weighting based on position within the block can be applied. That is, weighting can be applied at the pixel level. The weight applied to the MHP-Intra prediction block is represented by w, and when different weight information is provided for each region, it is represented as wN (N>=0). Therefore, the weights applied to each of the two-part regions can be represented as w0 and w1, and the weights applied to each of the three-part regions can be represented as w0, w1, and w2. The above weights can be determined from signaled index information, or can be determined as fixed values ​​without signaling index information. Furthermore, they can be derived by considering the weights of adjacent blocks. The weight information applied to the additional prediction block of the adjacent block can be used as is, or based on the intra prediction mode. Specifically, for a mode predicted from an upper reference sample, the weight of the intra block can be set to be smaller as the distance from the upper side increases. Conversely, for a mode predicted from a left reference sample, the weight of the intra block can be set to be smaller as the distance from the left increases. In addition, when the adjacent block is encoded / decoded in intra mode, the weight of the MHP-intra prediction block can be set to be larger than when the adjacent block is encoded / decoded in inter mode or IBC mode. Alternatively, when the adjacent block is encoded / decoded in intra mode, the weight can be set to be large for samples close to the adjacent block. That is, the weight information can be applied to the entire current block, applied to each segmented region, or applied based on the position on a pixel-by-pixel basis. In addition, when applying the weight on a segmented region-by-region basis or on a pixel-by-pixel basis, the weight of a specific region and position can have a value of 0. In other words, there may be specific regions and positions to which the multi-prediction block mode is not applied. Additionally, when adjacent blocks are encoded / decoded in IBC mode, the weight of the MHP-IBC prediction block can be set to be greater than when adjacent blocks are encoded / decoded in inter mode or intra mode. Example 7 The present embodiment relates to a method for deriving a reference sample for generating a prediction block when an MHP-intra prediction block exists. FIG. 46 is a flowchart showing an example of a decoding method performed in MHP-intra mode in a decoding method according to one embodiment. Referring to Figure 46, a prediction mode applied to intra prediction is determined (S2300), and a reference sample corresponding to the determined prediction mode is generated (S2310). Using the generated reference sample, a prediction block is generated according to the prediction mode (S2320). Sample improvement can be achieved for the generated prediction block through boundary smoothing or PDPC (S2330). In the following embodiment, the process of generating a reference sample (S2310) is specifically described. To generate a reference sample, first, a reconstructed sample adjacent to the current block is used to fill in the reference sample. If a reference sample does not exist, the reference sample can be filled in from a neighboring sample using a predefined method. If a given condition is satisfied, filtering is performed on the reference sample. For example, a smoothing filter can be applied to correct the reference sample. Additionally, if the prediction mode requires reference samples at fractional-pel locations, an interpolation filter can be used to generate reference samples for each phase. The interpolation filter can be at least one of various filters, such as a cubic interpolation filter or a Gaussian interpolation filter. According to one embodiment, the strength and type of filtering can be determined using reference samples. FIG. 47 is a diagram illustrating an example of the locations of reference samples and samples within a base prediction block used to generate an MHP-intra prediction block. If the difference between the activity A0 of the reference sample used to generate the MHP-Intra prediction block and the activity A1 of the sample within the base prediction block is greater than a threshold (Tn, n>=0), the discontinuity between the adjacent sample and the base prediction block can be determined to be significant. The calculation of the sample's activity and the determination of whether filtering is applied can be performed using at least one of the following methods: - A0 and A1 are calculated as the variance of the samples within each region, and whether filtering is applied can be determined based on whether |A0 - A1| > T0. - A0 and A1 are calculated as the standard deviations of samples within each area, and whether filtering is applied can be determined based on whether |A0 - A1| > T1. - It is calculated as the SAD of the reference sample for the MHP-intra prediction block and the sample within the basic prediction block, and whether filtering is applied can be determined based on whether SAD > T2. - It is calculated as the SSE of the reference sample for the MHP-intra prediction block and the sample within the basic prediction block, and whether filtering is applied can be determined based on whether SSE > T3. At this time, when the number of reference samples for the MHP-intra prediction block and the number of samples within the basic prediction block are different, additional processes such as matching the number of samples or normalizing using the number of samples may be included. As illustrated in Fig. 47, the range of reference samples used for calculating the activity of the samples may be variably determined depending on the intra prediction mode. Figure 48 illustrates an example of changing the location of a sample in a base prediction block to an area adjacent to the prediction block to compare activity between samples corresponding to the same location. The aforementioned methods of calculating activity in samples and applying normalization based on the number of samples can be applied in the same manner. Depending on the degree of discontinuity and the prediction mode, which are separated by K (integers where K > 0) thresholds, filtering can be applied to the reference samples in the following way: - Unfiltered reference samples can be used as is. - The applied filter can be [1, 2, 1] / 4. - The applied filter can be [2, 3, 6, 3, 2] / 16. - The applied filter can be a strong filter. Figure 49 shows an example of applying a strong filter to the current block. Reference samples can be generated based on the distance ratio using reference samples in the upper left and upper right or upper left and lower left. In the example of Figure 49, 63 can be applied by changing it to ((width * m) - 1), ((height * m) - 1) of the block. (m > 1 is an integer) Meanwhile, the aforementioned embodiment can be equally applied to the MHP-IBC prediction mode. Accordingly, at least one of the MHP-Intra prediction mode or the MHP-IBC prediction mode can be included in the additional prediction mode for generating an additional prediction block, and the aforementioned method can also be applied when generating a prediction block using the MHP-IBC prediction mode. Example 8 The present embodiment relates to a filtering method in the process of generating a prediction block when an intra prediction block exists as an additional prediction block, i.e., when an MHP-intra prediction block exists. Intra prediction modes, especially directional prediction modes, have a problem of discontinuity occurring in areas (or boundaries) that are not adjacent to reference samples. To address this, as previously described with reference to Figure 46, techniques such as boundary smoothing or PDPC can be applied to the boundaries of the generated intra prediction blocks. In other words, sample improvement for a prediction block during the decoding process described above can generate a corrected prediction block by improving some samples based on the generated prediction block using at least one of boundary smoothing or PDPC. In one embodiment, the proposed method can be applied to a sample enhancement process for a prediction block. Specifically, after generating a prediction block using the MHP-Intra mode, enhancement with boundary filtering characteristics can be applied to the prediction block. To this end, information regarding the filter applied to the MHP-Intra prediction block (e.g., mhp_filter_flag or mhp_filter_idx) can be signaled / parsed. Figure 50 is a flowchart illustrating an example of the operation of signaling / parsing filtering information for MHP-Intra mode. Referring to FIG. 50, MHP-Intra information (e.g., mhp_intra_flag) is signaled / parsed (S2400), and if the MHP-Intra information indicates application of the MHP-Intra mode, for example, if the value of mhp_intra_flag is 1 (example of S2410), MHP-Intra filter information can be signaled / parsed (S2430). The MHP-Intra filter information indicates information about a filter applied to an MHP-Intra prediction block, and can include, for example, syntax elements such as mhp_filter_flag. For example, when the value of mhp_filter_flag is 1, a pixel location-based enhancement process within the MHP-intra prediction block can be performed using a predefined filter. When the value of mhp_filter_flag is 0, simplified boundary filtering or no filtering can be applied. The method described in the present embodiment can be combined with the previously described embodiments. For example, it can be signaled / parsed together with all or part of the syntax elements such as prediction mode information of the MHP-intra mode, mhp_mpm_flag, mhp_not_planar_flag, mhp_mpm_idx, mhp_mpm_remainder, etc. In addition, it can be signaled / parsed together with the weight information applied to the MHP-intra prediction block, such as intra_weight_idx, intra_weight_idx0, intra_weight_idx1, etc. In addition, it goes without saying that the various previously described embodiments and the MHP-intra filter information described in the present embodiment can be applied together. Figure 51 is a flowchart illustrating another example of the operation of signaling / parsing filtering information for MHP-Intra mode. According to the example of Fig. 51, a process of determining a predetermined condition (S2420) before signaling / parsing (S2430) MHP-intra filter information may be added to the process illustrated in Fig. 49 described above. Accordingly, in the example, if the predetermined condition is satisfied (example of S2420), MHP-intra filter information (e.g., mhp_intra_flag) may be signaled / parsed (S2430). The conditions used to determine whether to signal / parse MHP-Intra filter information can be determined by applying at least one of the following methods: - The above conditions can be determined based on information such as the size of the current block (width x height), the width and height of the block, and the ratio of the block (width / height or height / width). For example, if the block size is less than 32, the MHP-Intra filter information may not be signaled / parsed. Alternatively, if the block size is greater than 1024, the MHP-Intra filter information may not be signaled / parsed. - The above conditions may be determined according to the prediction mode of the current block. For example, if a prediction mode such as MMVD, GPM (GPM-INTRA), or CIIP is applied to the current block, MHP-Intra filter information may not be signaled / parsed. As another example, if a subblock-based prediction mode is applied, MHP-Intra filter information may not be signaled / parsed. In addition, MHP-Intra filter information may not be signaled / parsed in the AMVP mode, which has high motion accuracy due to MVD. In addition, MHP-Intra filter information may not be signaled / parsed in the block, such as DMVR and BDOF, where motion information improvement or prediction sample improvement is applied. - The above conditions can be determined based on the prediction direction of the current block. For example, whether to signal / parse mhp_filter_flag can be determined depending on whether unidirectional prediction or bidirectional prediction is applied. For example, mhp_filter_flag can be signaled / parsed when unidirectional prediction is applied, and not signaled / parsed when bidirectional prediction is applied. - The above condition can be determined based on the BCW (Bi-prediction with CU-level Weight) index of the current block. For example, mhp_filter_flag can be signaled / parsed when the BCW index does not indicate a specific value. - The above conditions can be determined based on the LIC (Local Illumination Compensation) flag information of the current block. For example, if LIC is applied, mhp_filter_flag can be signaled / parsed. - The above conditions may be determined based on the OBMC (Overlapped Block Motion Compensation) flag information of the current block. For example, if OBMC is applied, mhp_filter_flag may not be signaled / parsed. - The above conditions may be determined based on the number of additional prediction blocks. When multiple MHP-intra prediction blocks exist, mhp_filter_flag may not be signaled / parsed. Alternatively, when MHP-inter prediction blocks exist, mhp_filter_flag may not be signaled / parsed. The sample enhancement method applied to an MHP-intra prediction block can be determined from signaled information as described above, or can be determined as a fixed value without signaling. Furthermore, it can be derived by considering filter information of adjacent blocks. For example, the filter information of adjacent blocks can be used as is. Furthermore, filter information determined based on the directionality of the intra prediction mode can be used. For example, when vertical directional mode is applied, the prediction block is generated using the upper reference sample, which may result in a relatively large discontinuity with the left adjacent sample. Therefore, the sample at the corresponding position can be enhanced to compensate for this. For another example, when horizontal directional mode is applied, the prediction block is generated using the left reference sample, which may result in a large discontinuity with the upper adjacent sample. Therefore, the sample at the corresponding position can be enhanced to compensate for this. In this case, the range of enhancement values ​​may be larger as the block gets closer to the boundary. The sample improvement method can be applied to all samples within a block or to only a specific region. Furthermore, the range of improved values ​​can vary depending on the sample's location. For example, as mentioned earlier, the closer a sample is to the block boundary, the greater the range of improved values. Meanwhile, the aforementioned embodiment can be equally applied to the MHP-IBC prediction mode. Accordingly, at least one of the MHP-Intra prediction mode or the MHP-IBC prediction mode can be included in the additional prediction mode for generating additional prediction blocks, and filtering information can be signaled / parsed in the same manner as described above even when applying the MHP-IBC prediction mode. Although the embodiments have been described separately for convenience of explanation so far, a combination of two or more embodiments is possible, and changes required by the combination of embodiments may also be included in the scope of the disclosed invention or disclosed embodiments. FIG. 52 is a diagram illustrating an example of a content streaming system to which an embodiment according to the present disclosure can be applied. Referring to FIG. 52, a content streaming system to which the embodiment(s) of the present specification are applied may largely include an encoding server, a streaming server, a web server, a media storage, a user device, and a multimedia input device. The encoding server compresses content input from multimedia input devices such as smartphones, cameras, and camcorders into digital data, generates a bitstream, and transmits it to the streaming server. Alternatively, if multimedia input devices such as smartphones, cameras, and camcorders directly generate bitstreams, the encoding server may be omitted. The above bitstream can be generated by an encoding method or a bitstream generation method to which the embodiment(s) of the present specification are applied, and the streaming server can temporarily store the bitstream during the process of transmitting or receiving the bitstream. The streaming server transmits multimedia data to a user device based on a user request via a web server, and the web server acts as an intermediary to inform the user of available services. When a user requests a desired service from the web server, the web server transmits the request to the streaming server, and the streaming server transmits the multimedia data to the user. At this time, the content streaming system may include a separate control server, in which case the control server controls commands / responses between each device within the content streaming system. The streaming server can receive content from a media repository and / or an encoding server. For example, when receiving content from the encoding server, the content can be received in real time. In this case, to provide a smooth streaming service, the streaming server can store the bitstream for a certain period of time. Examples of the user devices may include mobile phones, smart phones, laptop computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation devices, slate PCs, tablet PCs, ultrabooks, wearable devices (e.g., smartwatches, smart glasses, HMDs), digital TVs, desktop computers, digital signage, etc. Each server within the above content streaming system can be operated as a distributed server, in which case data received from each server can be processed in a distributed manner. The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method. Embodiments according to the present disclosure can be used to encode / decode images.

Claims

1. Obtain information about the basic prediction mode; Generate a basic prediction block based on information about the above basic prediction mode; Obtain information about additional prediction modes; Generating an additional prediction block based on information about the above additional prediction mode; and generating a final prediction block based on a combination of the above basic prediction block and the above additional prediction block; The above additional prediction mode is, Contains at least one of intra prediction mode or IBC prediction mode, Information about the above additional prediction modes is: A decoding method comprising at least one of information indicating whether the intra prediction mode is applied to the generation of the additional prediction block or information indicating whether the IBC prediction mode is applied to the generation of the additional prediction block.

2. In paragraph 1, Obtaining information about the above additional prediction mode is: A decoding method comprising obtaining information indicating whether the intra prediction mode is applied to the generation of the additional prediction block or information indicating whether the IBC prediction mode is applied to the generation of the additional prediction block prior to information indicating whether the inter prediction mode is applied to the generation of the additional prediction block.

3. In paragraph 1, Obtaining information about the above additional prediction mode is: Judge the given conditions; A decoding method comprising: obtaining at least one of information indicating whether the intra prediction mode is applied to the generation of the additional prediction block or information indicating whether the tkdrl IBC prediction mode is applied, based on the above-determined condition being satisfied; 4. In paragraph 1, Obtaining information about the above additional prediction mode is: A decoding method comprising obtaining information indicating whether an inter prediction mode is applied to the generation of the additional prediction block prior to at least one of information indicating whether the intra prediction mode is applied to the generation of the additional prediction block or information indicating whether the IBC prediction mode is applied.

5. In paragraph 1, Information about the above additional prediction modes is: Contains information about at least one detailed prediction mode among the intra prediction mode or the IBC prediction mode used in generating the additional prediction block, Obtaining information about the above additional prediction mode is: A decoding method comprising obtaining information about a detailed prediction mode of at least one of the applied intra prediction mode or the IBC prediction mode, based on the application of at least one of the intra prediction mode or the IBC prediction mode to the generation of the additional prediction block.

6. In paragraph 1, Information about the above additional prediction modes is: Including weight information for the intra additional prediction block or the IBC additional prediction block generated by applying at least one of the intra prediction mode or the IBC prediction mode, Generating a final prediction block based on the combination of the above basic prediction block and the above additional prediction block, A decoding method comprising weighting the basic prediction block and the additional prediction block based on the weight information.

7. In paragraph 6, The above weight information is, Contains multiple different weight values, Generating the final prediction block above is: A decoding method comprising applying different weight values ​​to a plurality of divided regions obtained by dividing the intra additional prediction block or the IBC additional prediction block.

8. Based on the prediction mode for the current block being determined as merge mode, information about the prediction is derived from the surrounding blocks; and generating a prediction block for the current block based on information about a prediction derived from the surrounding blocks; Generating a prediction block for the current block above is: A decoding method comprising applying a multi-prediction block mode to the current block based on information about a prediction derived from the surrounding blocks including information about a multi-prediction block mode.

9. In paragraph 8, Deriving information about prediction from the surrounding blocks above, Determine whether the specified conditions are satisfied; A decoding method comprising: deriving information about the multi-prediction block mode based on satisfaction of the above-determined condition.

10. In paragraph 8, Deriving information about prediction from the surrounding blocks above, Determine whether the specified conditions are satisfied; A decoding method comprising: deriving information about an intra prediction mode or an IBC prediction mode from among information about the multi-prediction block mode based on the above-determined conditions being satisfied; 11. Generate information indicating whether the multi-prediction block mode is applied to the current block; Based on the application of the above multi-prediction block mode, information about a basic prediction mode used to generate a basic prediction block and information about an additional prediction mode used to generate an additional prediction block are generated; and Encoding information indicating whether the above multi-prediction block mode is applied, information about the basic prediction mode, and information about the additional prediction mode; The above additional prediction mode is, Contains at least one of intra prediction mode or IBC prediction mode, Information about the above additional prediction modes is: An encoding method comprising at least one of information indicating whether the intra prediction mode is applied to the generation of the additional prediction block or information indicating whether the IBC prediction mode is applied to the generation of the additional prediction block.

12. Based on the prediction mode for the current block being determined as the merge mode, information indicating that the merge mode is applied to the current block and a merge candidate list are generated; Selecting one of the candidates included in the above merge candidate list and generating information representing the selected candidate; and Encoding information indicating that the above merge mode is applied and information indicating the selected candidate; The above selected candidates are, Corresponds to the surrounding blocks to which the multi-prediction block mode is applied, Information about the multi-prediction block mode applied to the above selected candidate, An encoding method derived as information regarding the prediction of the current block.

13. A computer-readable recording medium storing a bitstream, wherein the bitstream comprises: Information indicating whether multi-prediction block mode is applied to the current block; Information about the base prediction mode used to generate the base prediction block; and Information about the additional prediction mode used to generate the additional prediction block; The above additional prediction mode is, Contains at least one of intra prediction mode or IBC prediction mode, Information about the above additional prediction modes is: A computer-readable recording medium comprising at least one of information indicating whether the intra prediction mode is applied to the generation of the additional prediction block or information indicating whether the IBC prediction mode is applied to the generation of the additional prediction block.

14. A computer-readable recording medium storing a bitstream, wherein the bitstream comprises: Information indicating that the above merge mode is applied to the current block; Information indicating one candidate selected from among the candidates included in the merge candidate list; and Information regarding the prediction of the above selected candidate; The above selected candidates are, Corresponds to the surrounding blocks to which the multi-prediction block mode is applied, Information about the multi-prediction block mode applied to the above selected candidate, A computer-readable recording medium derived as information regarding the prediction of the current block.

15. In the method of transmitting video information, Generating the image information including a bitstream, wherein the bitstream includes information indicating whether a multi-prediction block mode is applied to a current block, information about a basic prediction mode used to generate a basic prediction block, and information about an additional prediction mode used to generate an additional prediction block; and Transmitting image information including the above bitstream; The above additional prediction mode is, Contains at least one of intra prediction mode or IBC prediction mode, Information about the above additional prediction modes is: A transmission method comprising at least one of information indicating whether the intra prediction mode is applied to the generation of the additional prediction block or information indicating whether the IBC prediction mode is applied.

16. In the method of transmitting video information, Generating the image information including a bitstream, wherein the bitstream includes information indicating whether the merge mode is applied to the current block, information indicating one candidate selected from among candidates included in the merge candidate list, and information regarding the prediction of the selected candidate; and Transmitting image information including the above bitstream; The above selected candidates are, Corresponds to the surrounding blocks to which the multi-prediction block mode is applied, Information about the multi-prediction block mode applied to the above selected candidate, A transmission method derived as information regarding the prediction of the current block.

Images