Image / video encoding / decoding method and device

Abstract

The video decoding method performed by the video decoding device according to the present document may include: parsing from a bitstream quantity information related to an explicitly signaled height for a slice in a patch of a current picture; based on the quantity information, parsing from the bitstream height information related to an explicitly signaled height for the slice; deriving heights of the 0th to (n‑1)th slices in the patch based on the height information; deriving the height of the nth slice in the patch based on the height of the (n‑1)th slice; and deriving the height of the last slice in the patch based on the remaining height.

Description

Technical Field

[0001] The present disclosure relates to a method and device for encoding / decoding an image / video. Background Art

[0002] Recently, the demand for high-resolution, high-quality images / videos such as 4K or 8K or above ultra-high definition (UHD) images / videos is increasing in various fields. As the image / video resolution or quality becomes higher, a relatively larger amount of information or bits is transmitted compared to conventional image / video data. Therefore, if the image / video data is transmitted via a medium such as an existing wired / wireless broadband line or is stored in a traditional storage medium, the cost for transmission and storage is easily increased.

[0003] In addition, there is growing interest and demand for virtual reality (VR) and artificial reality (AR) content and immersive media such as holograms; and there is also growing broadcasting of images / videos that exhibit image / video characteristics that are different from actual images / videos (e.g., game images / videos).

[0004] Therefore, highly efficient image / video compression technology is required to effectively compress and transmit, store, or play high-resolution, high-quality images / videos showing various characteristics as described above. Summary of the invention

[0005] Technical issues

[0006] The technical purpose of the present disclosure is to provide a method and device for increasing the coding efficiency of images / videos.

[0007] Another technical object of the present disclosure is to provide a method and apparatus for efficiently signaling information about slices within a tile.

[0008] Yet another technical objective of the present disclosure is to provide a method and apparatus for reducing signaling overhead when delivering (or transmitting) information about slices within a tile.

[0009] Technical Solution

[0010] According to an embodiment of the present specification, a video decoding method performed by a video decoding device is provided. The method may include the following steps: parsing quantity information related to the number of slices whose heights of each slice are explicitly signaled within a patch of a current picture from a bitstream; parsing height information related to the heights of slices whose heights of each slice are explicitly signaled from the bitstream based on the quantity information; deriving the heights of the 0th slice to the (n-1)th slice within the patch based on the height information based on the value of the quantity information being equal to n; deriving the height of the nth slice within the patch based on the height of the (n-1)th slice; deriving the height of the last slice within the patch based on the remaining height after subtracting the heights of other slices within the patch from the height of the patch; deriving the number of slices within the patch; and decoding the current picture based on the slices of the current picture.

[0011] According to another embodiment of the present specification, a video encoding method performed by a video encoding device is provided herein. The method may include the following steps: deriving slices within a patch of a current picture; generating quantity information related to the number of slices within the patch whose heights of each slice are explicitly signaled based on the derived slices and height information related to the height of the slices whose heights of each slice are explicitly signaled; and encoding image information including the quantity information and the height information, wherein the height information may indicate the heights of the 0th slice to the (n-1)th slice within the patch based on the value of the quantity information being equal to n, and wherein the height of the nth slice within the patch is derived based on the height of the (n-1)th slice.

[0012] According to another embodiment of the present specification, a computer-readable digital recording medium is provided herein, having information stored therein for causing a video decoding method to be executed by a video decoding device, wherein the video decoding method may include the following steps: parsing quantity information related to the number of slices whose each slice height is explicitly sent with a signal within a patch of a current picture from image information; parsing height information related to the height of slices whose each slice height is explicitly sent with a signal from image information based on the quantity information; deriving heights of the 0th slice to the (n-1)th slice within the patch based on the height information based on the value of the quantity information being equal to n; deriving the height of the nth slice within the patch based on the height of the (n-1)th slice; deriving the height of the last slice within the patch based on the remaining height after subtracting the heights of other slices within the patch from the height of the patch; deriving the number of slices within the patch; and decoding the current picture based on the slices of the current picture.

[0013] Beneficial Effects

[0014] According to the embodiments of the present disclosure, the overall compression efficiency of images / videos can be enhanced.

[0015] According to an embodiment of the present disclosure, information about slices within a tile can be efficiently signaled.

[0016] According to an embodiment of the present disclosure, signaling overhead may be reduced when delivering (or transmitting) information about slices within a tile. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 An example of a video / image coding system to which embodiments of the present disclosure may be applied is schematically shown.

[0018] Figure 2 is a diagram schematically illustrating a configuration of a video / image encoding device to which an embodiment of the present disclosure can be applied.

[0019] Figure 3 is a diagram schematically illustrating a configuration of a video / image decoding device to which an embodiment of the present disclosure can be applied.

[0020] Figure 4 An example of a picture decoding process is shown.

[0021] Figure 5 An example of a picture encoding process is shown.

[0022] Figure 6 and Figure 7 General examples of video / image encoding methods and related components according to embodiments of the present disclosure are respectively shown.

[0023] Figure 8 and Fig. 9 General examples of video / image decoding methods and related components according to embodiments of the present disclosure are respectively shown.

[0024] Fig.10 An example of a content streaming system to which an embodiment of the present disclosure can be applied is shown. DETAILED DESCRIPTION

[0025] The disclosure of the present disclosure can be modified in various forms, and specific embodiments thereof will be described and illustrated in the accompanying drawings. The terms used in the present disclosure are only used to describe specific embodiments and are not intended to limit the disclosed methods in the present disclosure. Singular expressions include the expression of "at least one", as long as it is clearly interpreted differently. Terms such as "including" and "having" are intended to indicate the presence of features, quantities, steps, operations, elements, components, or combinations thereof used in the document, and therefore it should be understood that the possibility of the presence or addition of one or more different features, quantities, steps, operations, elements, components, or combinations thereof is not excluded.

[0026] In addition, each configuration of the drawings described in this document is an independent illustration for explaining the functions of features that are different from each other, and does not mean that each configuration is implemented by different hardware or different software. For example, two or more configurations can be combined to form a configuration, and a configuration can also be divided into multiple configurations. Without departing from the gist of the disclosed method of the present disclosure, embodiments of combined and / or separated configurations are included within the scope of the disclosure of the present disclosure.

[0027] In this document, the terms " / " and "," should be interpreted as indicating "and / or". For example, the expression "A / B" may mean "A and / or B". Furthermore, "A, B" may mean "A and / or B". Furthermore, "A / B / C" may mean "at least one of A, B, and / or C". Furthermore, "A / B / C" may mean "at least one of A, B, and / or C".

[0028] Furthermore, in this document, the term "or" should be interpreted as indicating "and / or". For example, the expression "A or B" may include 1) only A, 2) only B, and / or 3) both A and B. In other words, the term "or" in this document should be interpreted as indicating "additionally or alternatively".

[0029] In addition, brackets used in this specification may mean "for example". Specifically, in the case of expressing "prediction (intra-frame prediction)", it may indicate that "intra-frame prediction" is proposed as an example of "prediction". In other words, the term "prediction" in this specification is not limited to "intra-frame prediction", and it may indicate that "intra-frame prediction" is proposed as an example of "prediction". In addition, even in the case of expressing "prediction (i.e., intra-frame prediction)", it may indicate that "intra-frame prediction" is proposed as an example of "prediction".

[0030] In this document, technical features explained separately in one drawing may be implemented separately or simultaneously.

[0031] Hereinafter, embodiments of the present document will be described in detail with reference to the accompanying drawings. In addition, in all drawings, the same reference numerals may be used to indicate the same elements, and the same description of the same elements will be omitted.

[0032] Figure 1 An example of a video / image coding system to which embodiments of the present disclosure can be applied is illustrated.

[0033] Reference Figure 1 The video / image coding system may include a first device (source device) and a second device (receiving device). The source device may send the encoded video / image information or data in the form of a file or stream to the receiving device via a digital storage medium or a network.

[0034] The source device may include a video source, an encoding device, and a transmitter. The receiving device may include a receiver, 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, and the display may be configured as a separate device or an external component.

[0035] The video source may acquire the video / image by capturing, synthesizing or generating a video / image process. The video source may include a video / image capture device and / or a video / image generation device. For example, the video / image capture device may include one or more cameras, a video / image archive including previously captured videos / images, etc. For example, the video / image generation device may include a computer, a tablet computer, and a smart phone, and may (electronically) generate the video / image. For example, a virtual video / image may be generated by a computer, etc. In this case, the video / image capture process may be replaced by a process that generates relevant data.

[0036] The encoding device can encode the input video / image. For compression and coding efficiency, the encoding device can perform a series of processes such as prediction, transformation and quantization. The encoded data (encoded video / image information) can be output in the form of a bitstream.

[0037] The transmitter may transmit the encoded image / image information or data output in the form of a bit stream to a receiver of a receiving device in the form of a file or stream through a digital storage medium or a network. The digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD, etc. The transmitter may include an element for generating a media file in a predetermined file format, and may include an element for transmitting through a broadcast / communication network. The receiver may receive / extract a bit stream and transmit the received bit stream to a decoding device.

[0038] The decoding device may decode a video / image by performing a series of processes such as dequantization, inverse transformation, and prediction corresponding to the operations of the encoding device.

[0039] The renderer can render the decoded video / image. The rendered video / image can be displayed by a display.

[0040] This document relates to video / image coding. For example, the methods / embodiments disclosed in this document can be applied to the methods disclosed in the Versatile Video Coding (VVC) standard. In addition, the methods / embodiments disclosed in this document can be applied to the Basic Video Coding (EVC) standard, the AOMedia Video 1 (AV1) standard, the second generation audio video coding standard (AVS2), or the next generation video / image coding standard (e.g., H.267, H.268, etc.).

[0041] Various embodiments related to video / image coding are presented in this document, and the embodiments can be combined with each other unless otherwise stated.

[0042] In this document, video may refer to a series of images over a period of time. A picture generally refers to a unit that represents an image in a specific time frame, and a slice / tile refers to a unit that constitutes a part of a picture in terms of coding. A slice / tile may include one or more coding tree units (CTUs). A picture may consist of one or more slices / tiles. A picture may consist of one or more tile groups. A tile group may include one or more tiles. A tile may represent a rectangular area of ​​a CTU row within a tile in a picture. A tile may be partitioned into multiple tiles, each of which consists of one or more CTU rows within the tile. Tiles that are not partitioned into multiple tiles may also be referred to as tiles. Tile scanning is a specific ordering of CTUs of partitioned pictures, where CTUs are continuously sorted in a CTU raster scan in a tile, tiles within a tile are continuously sorted in a raster scan of tiles of a tile, and tiles in a picture are continuously sorted in a raster scan of tiles of a tile. A patch is a rectangular area of ​​a CTU within a specific patch column and a specific patch row in a picture. A patch column is a rectangular area of ​​a CTU whose height is equal to the height of the picture and whose width is specified by a syntax element in the picture parameter set. A patch row is a rectangular area of ​​a CTU whose height is specified by a syntax element in the picture parameter set and whose width is equal to the width of the picture. Patch scan is a specific sequential ordering of CTUs of a partitioned picture, where CTUs are ordered continuously in a raster scan of CTUs in patches, and patches in a picture are ordered continuously in a raster scan of patches of a picture. A slice includes an integer number of tiles of a picture, which can be exclusively contained in a single NAL unit. A slice can consist of multiple complete patches, or only a continuous sequence of complete tiles of a patch. In this document, patch groups and slices can be used interchangeably. For example, in this document, a patch group / patch group header can be referred to as a slice / slice header.

[0043] A pixel or a picture element (pel) may refer to the smallest unit constituting a picture (or image). In addition, a "sample" may be used as a term corresponding to a pixel. A sample may generally represent a pixel or a pixel value, and may represent only a pixel / pixel value of a luminance component or only a pixel / pixel value of a chrominance component.

[0044] A unit may represent a basic unit of image processing. A unit may include at least one of a specific area of ​​a picture and information related to the area. A unit may include a luminance block and two chrominance (e.g., cb, cr) blocks. In some cases, a unit may be used interchangeably with terms such as a block or an area. In general, an M×N block may include M columns and N rows of samples (or sample arrays) or a set (or array) of transform coefficients. Alternatively, a sample may refer to a pixel value in a spatial domain, and when such a pixel value is transformed to a frequency domain, it may refer to a transform coefficient in a frequency domain.

[0045] In some cases, a unit may be used interchangeably with terms such as a block or region. In general, an M×N block may represent a set of samples or transform coefficients consisting of M columns and N rows. A sample may generally represent a pixel or a pixel value, and may represent only a pixel / pixel value of a luminance component or only a pixel / pixel value of a chrominance component. A sample may be used as a term corresponding to one picture (or image) of a pixel or a pixel element.

[0046] Figure 2 is a diagram schematically illustrating a configuration of a video / image encoding device to which an embodiment of the present disclosure may be applied. Hereinafter, a device referred to as a video encoding device may include an image encoding device.

[0047] Reference Figure 2 , the encoding device 200 includes an image partitioner 210, a predictor 220, a residual processor 230 and an entropy encoder 240, an adder 250, a filter 260 and a memory 270. The predictor 220 may include an inter-frame predictor 221 and an intra-frame predictor 222. The residual processor 230 may include a transformer 232, a quantizer 233, a dequantizer 234 and an inverse transformer 235. The residual processor 230 may also include a subtractor 231. The adder 250 may be referred to as a reconstructor or a reconstructed block generator. According to an embodiment, the image partitioner 210, the predictor 220, the residual processor 230, the entropy encoder 240, the adder 250 and the filter 260 may be configured by at least one hardware component (e.g., an encoder chipset or processor). In addition, the memory 270 may include a decoded picture buffer (DPB), or may be configured by a digital storage medium. The hardware component may also include a memory 270 as an internal / external component.

[0048] The image partitioner 210 may partition an input image (or picture or frame) input to the encoding device 200 into one or more processing units. For example, a processing unit may be referred to as a coding unit (CU). In this case, the coding unit may be recursively partitioned from a coding tree unit (CTU) or a maximum coding unit (LCU) according to a quadtree binary tree ternary tree (QTBTTT) structure. For example, one coding unit may be partitioned into a plurality of coding units with a deeper depth based on a quadtree structure, a binary tree structure, and / or a ternary structure. In this case, for example, a quadtree structure may be applied first, and a binary tree structure and / or a ternary structure may be applied later. Alternatively, a binary tree structure may be applied first. The coding process according to the present disclosure may be performed based on a final coding unit that is no longer partitioned. In this case, the maximum coding unit may be used as the final coding unit based on coding efficiency, etc. according to image characteristics, or if necessary, the coding unit may be recursively partitioned into coding units with a deeper depth and a coding unit with an optimal size may be used as the final coding unit. Here, the coding process may include a process of prediction, transformation, and reconstruction (to be described later). As another example, the processing unit may further include a prediction unit (PU) or a transform unit (TU). In this case, each of the prediction unit and the transform unit may be split or partitioned from the above-mentioned final coding unit. The prediction unit may be a unit for 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 the transform coefficient.

[0049] The encoding device 200 may subtract a prediction signal (prediction block, prediction sample array) output from the inter predictor 221 or the intra predictor 222 from the input image signal (original block, original sample array) to generate a residual signal (residual block, residual sample array), and the generated residual signal is sent to the transformer 232. In this case, as shown, the unit that subtracts the prediction signal (prediction block, prediction sample array) from the input image signal (original block, original sample array) in the encoder 200 may be referred to as a subtractor 231. The predictor may perform prediction on a processing target block (hereinafter referred to as a current block) and generate a prediction block including prediction samples of the current block. The predictor may determine whether intra prediction or inter prediction is applied in units of the current block or CU. As described later in the description of each prediction mode, the predictor may generate various types of information (e.g., prediction mode information) about prediction and send the generated information to the entropy encoder 240. The information about the prediction may be encoded by the entropy encoder 240 and output in the form of a bitstream.

[0050] The intra-frame predictor 222 may predict the current block with reference to samples in the current picture. Depending on the prediction mode, the referenced samples may be located near the current block or may be spaced apart. In intra-frame prediction, the prediction mode may include multiple non-directional modes and multiple directional modes. For example, the non-directional mode may include a DC mode and a plane mode. For example, depending on the level of detail of the prediction direction, the directional mode may include 33 directional prediction modes or 65 directional prediction modes. However, this is only an example, and more or fewer directional prediction modes may be used depending on the settings. The intra-frame predictor 222 may use the prediction mode applied to the neighboring blocks to determine the prediction mode applied to the current block.

[0051] The inter-frame predictor 221 may derive a prediction block of the current block based on a reference block (reference sample array) specified by a motion vector on a reference picture. Here, in order to reduce the amount of motion information sent in the inter-frame prediction mode, the motion information may 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 a reference picture index. The motion information may also include inter-frame prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.) information. In the case of inter-frame prediction, the neighboring blocks may include spatial neighboring blocks present in the current picture and temporal neighboring blocks present 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. The temporal neighboring block may be referred to as a collocated reference block, a collocated CU (colCU), etc., and the reference picture including the temporal neighboring block may be referred to as a collocated picture (colPic). For example, the inter-frame predictor 221 may configure a motion information candidate list based on the 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-frame prediction may be performed based on various prediction modes. For example, in the case of skip mode and merge mode, the inter-frame predictor 221 may use the motion information of the neighboring block as the motion information of the current block. In skip mode, unlike merge mode, a residual signal may not be transmitted. The motion vector prediction (MVP) mode may indicate the motion vector of the current block by using the motion vector of the neighboring block as a motion vector predictor and signaling the motion vector difference.

[0052] The predictor 220 may generate a prediction signal based on various prediction methods described later. For example, the predictor 220 may apply intra prediction or inter prediction to predict a block, and may apply intra prediction and inter prediction at the same time. This may be referred to as combined inter and intra prediction (CIIP). In addition, the predictor may be based on an intra block copy (IBC) prediction mode or based on a palette mode for predicting blocks. The IBC prediction mode or the palette mode may be used for image / video coding of content such as games, such as screen content coding (SCC). IBC basically performs prediction in the current picture, but it may be performed similarly to inter prediction in that a reference block is derived in the current picture. That is, IBC may use at least one of the inter prediction techniques described in this document. The palette mode may be considered an example of intra coding or intra prediction. When the palette mode is applied, the sample values ​​in the picture may be signaled based on information about the palette table and the palette index.

[0053] The prediction signal generated by the predictor (including the inter-frame predictor 221 and / or the intra-frame predictor 222) may be used to generate a reconstructed signal or may be used to generate a residual signal.

[0054] The transformer 232 may generate transform coefficients by applying a transform technique to the residual signal. For example, the transform technique may include at least one of a discrete cosine transform (DCT), a discrete sine transform (DST), a graph-based transform (GBT), or a conditional nonlinear transform (CNT). Here, when the relationship information between pixels is illustrated as a graph, GBT means a transform obtained from a graph. CNT means a transform obtained based on a prediction signal generated by using all previously reconstructed pixels. In addition, the transform process may also be applied to square pixel blocks of the same size, or may also be applied to variable-sized blocks that are not square.

[0055] The quantizer 233 quantizes the transform coefficients and transmits the quantized transform coefficients to the entropy encoder 240, and the entropy encoder 240 encodes the quantized signal (information about the quantized transform coefficients) and outputs the encoded signal as a bitstream. The information about the quantized transform coefficients may be referred to as residual information. The quantizer 233 may rearrange the quantized transform coefficients having a block form in a one-dimensional vector form based on a coefficient scanning order, and also generate information about the quantized transform coefficients based on the quantized transform coefficients in a one-dimensional vector form.

[0056] The entropy encoder 240 may perform various encoding methods such as, for example, exponential Golomb, context adaptive variable length coding (CAVLC), and context adaptive binary arithmetic coding (CABAC). The entropy encoder 240 may also encode information necessary for video / image reconstruction (e.g., values ​​of syntax elements, etc.) in addition to quantized transform coefficients, together or separately. The encoded information (e.g., encoded video / image information) may be transmitted or stored in units of a network abstraction layer (NAL) in the form of a bitstream. The video / image information may also include information about 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 also include general constraint information. In this document, information and / or syntax elements signaled / sent from an encoding device to a decoding device may be included in the video / image information. The video / image information may be encoded by the aforementioned encoding process and thus included in the bitstream. The bitstream may be transmitted over a network or may be stored in a digital storage medium. Here, the network may include a broadcast network and / or a communication network, and the digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, SSD, etc. A transmitting unit (not shown) for transmitting a signal output from the entropy encoder 240 and / or a storage unit (not shown) for storing the signal may be configured as an internal / external element of the encoding device 200, or the transmitting unit may also be included in the entropy encoder 240.

[0057] The quantized transform coefficients output from the quantizer 233 can be used to generate a prediction signal. For example, the residual signal (residual block or residual sample) can be reconstructed by applying dequantization and inverse transform to the quantized transform coefficients through the dequantizer 234 and the inverse transform unit 235. The adder 250 can add the reconstructed residual signal to the prediction signal output from the inter-frame predictor 221 or the intra-frame predictor 222 to generate a reconstructed signal (reconstructed picture, reconstructed block, reconstructed sample array). When there is no residual for the processing target block, such as when the skip mode is applied, the prediction block can be used as a reconstructed block. The adder 250 can be referred to as a restorer or a recovery block generator. The generated reconstructed signal can be used for intra-frame prediction of the next processing target block in the current picture, and can also be used for inter-frame prediction of the next picture after filtering, as described below.

[0058] Meanwhile, luminance mapping and chrominance scaling (LMCS) may also be applied during the picture encoding and / or reconstruction process.

[0059] The filter 260 can improve the subjective / objective image quality by applying filtering to the reconstructed signal. For example, the filter 260 can generate a modified reconstructed picture by applying various filtering methods to the reconstructed picture and store the modified reconstructed picture in the memory 270 (specifically, the DPB of the memory 270). For example, various filtering methods may include deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, etc. The filter 260 can generate various types of information related to filtering and transmit the generated information to the entropy encoder 240, as described later in the description of each filtering method. The information related to filtering can be encoded by the entropy encoder 240 and output in the form of a bit stream.

[0060] The modified reconstructed picture transmitted to the memory 270 may be used as a reference picture in the inter predictor 221. When inter prediction is applied by the encoding device, prediction mismatch between the encoding device 200 and the decoding device may be avoided and coding efficiency may be improved.

[0061] The DPB of the memory 270 may store the modified reconstructed picture for use as a reference picture in the inter-frame predictor 221. The memory 270 may store the motion information of the block from which the motion information in the current picture is derived (or encoded) and / or the motion information of the block in the reconstructed picture. The stored motion information may be transmitted to the inter-frame predictor 221 to be used as the motion information of the spatial neighboring block or the motion information of the temporal neighboring block. The memory 270 may store the reconstructed samples of the reconstructed block in the current picture, and may transmit the reconstructed samples to the intra-frame predictor 222.

[0062] Figure 3 is a diagram for schematically explaining a configuration of a video / image decoding device to which an embodiment of the present disclosure can be applied.

[0063] Reference Figure 3 , the decoding device 300 may 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-frame predictor 331 and an intra-frame predictor 332. The residual processor 320 may include a dequantizer 321 and an inverse transformer 321. According to an embodiment, the entropy decoding 310, the residual processor 320, the predictor 330, the adder 340, and the filter 350 may be configured by a hardware component (e.g., a decoder chipset or a processor). In addition, the memory 360 may include a decoded picture buffer (DPB) or may be configured by a digital storage medium. The hardware component may also include a memory 360 as an internal / external component.

[0064] When a bit stream including video / image information is input, the decoding device 300 may respond to the Figure 2Reconstruct an image according to the process of processing video / image information in the encoding device shown. For example, the decoding device 300 may derive units / blocks based on the block partition related information obtained from the bitstream. The decoding device 300 may perform decoding using the processing units applied to the encoding device. Thus, for example, the processing unit for decoding may be a compilation unit, and the compilation unit may be split from the compilation tree unit or the largest compilation unit according to a quadtree structure, a binary tree structure, and / or a ternary tree structure. One or more transform units may be derived from the compilation unit. In addition, the reconstructed image signal decoded and output by the decoding device 300 may be reproduced by a reproduction device.

[0065] The decoding device 300 may receive the signal output from the Figure 2 encoding device in the form of a bitstream, and may decode the received signal through the entropy decoder 310. For example, the entropy decoder 310 may parse the bitstream to derive the information (e.g., video / image information) required for image reconstruction (or picture reconstruction). The video / image information may also include information about 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). Additionally, the video / image information may also include general constraint information. The decoding device may also decode pictures based on the information about the parameter sets and / or the general constraint information. The information and / or syntax elements signaled / received described later in this document may be decoded through the decoding process and obtained from the bitstream. For example, the entropy decoder 310 may decode the information within the bitstream based on a compilation method such as exponential Golomb compilation, context-adaptive variable-length compilation (CAVLC), or context-adaptive binary arithmetic compilation (CABAC), and output the syntax elements required for image reconstruction and the quantization values of the transform coefficients for the residuals. More specifically, the CABAC entropy decoding method may receive the bins corresponding to each syntax element in the bitstream, determine the context model by using the decoding target syntax element information, the decoding information of the decoding target block, or the information of the symbols / bins decoded in the previous stage, and perform arithmetic decoding on the bins by predicting the probability of the appearance of the bins according to the determined context model, and generate symbols corresponding to the values of each syntax element. In this case, the CABAC entropy decoding method may update the context model by using the information of the decoded symbols / bins for the context model of the next symbol / bin after determining the context model. The information related to prediction among the information decoded by the entropy decoder 310 may be provided to the predictors (the inter-frame predictor 332 and the intra-frame predictor 331), and the residual values (i.e., the quantized transform coefficients and the related parameter information) for which the entropy decoder 310 has performed entropy decoding may be input to the residual processor 320.

[0066] The residual processor 320 may derive a residual signal (residual block, residual sample, residual sample array). In addition, information about filtering among the information decoded by the entropy decoder 310 may be provided to the filter 350. Meanwhile, a receiver (not shown) for receiving a signal output from the encoding device may also be configured as an internal / external element of the decoding device 300, or the receiver may be a component of the entropy decoder 310. Meanwhile, the decoding device according to this document may be referred to as a video / image / picture decoding device, and the decoding device may be classified into an information decoder (video / image / picture information decoder) and a sample decoder (video / image / picture sample decoder). The information decoder may include an entropy decoder 310, and the sample decoder may include at least one of the following: a dequantizer 321, an inverse transformer 322, an adder 340, a filter 350, a memory 360, an inter-frame predictor 332, and an intra-frame predictor 331.

[0067] The dequantizer 321 may dequantize the quantized transform coefficients and output the transform coefficients. The dequantizer 321 may rearrange the quantized transform coefficients in a two-dimensional block form. In this case, the rearrangement may be performed based on the coefficient scanning order performed in the encoding device. The dequantizer 321 may perform dequantization on the quantized transform coefficients using a quantization parameter (e.g., quantization step size information) and obtain the transform coefficients.

[0068] The inverse transformer 322 inversely transforms the transform coefficients to obtain a residual signal (residual block, residual sample array).

[0069] In this document, at least one of quantization / dequantization and / or transform / inverse transform may be omitted. When quantization / dequantization is omitted, the quantized transform coefficient may be referred to as a transform coefficient. When transform / inverse transform is omitted, the transform coefficient may be referred to as a coefficient or a residual coefficient, or may still be referred to as a transform coefficient for consistency of expression.

[0070] In this document, the quantized transform coefficient and the transform coefficient may be referred to as a transform coefficient and a scaled transform coefficient, respectively. In this case, the residual information may include information about the transform coefficient, and the information about the transform coefficient may be signaled through the residual coding syntax. The transform coefficient may be derived based on the residual information (or information about the transform coefficient), and the scaled transform coefficient may be derived by inverse transforming (scaling) the transform coefficient. The residual sample may be derived based on the inverse transform (transform) of the scaled transform coefficient. This may also be applied / expressed in other parts of this document.

[0071] The predictor 330 may perform prediction on the current block and generate a prediction block including prediction samples of the current block. The predictor may determine whether to apply intra prediction or inter prediction to the current block and determine a specific intra / inter prediction mode based on information on prediction output from the entropy decoder 310.

[0072] The predictor 330 may generate a prediction signal based on various prediction methods described below. For example, the predictor may apply intra prediction or inter prediction for predicting a block, and may apply intra prediction and inter prediction at the same time. This may be referred to as combined inter and intra prediction (CIIP). In addition, the predictor may predict a block based on an intra block copy (IBC) prediction mode or a palette mode. The IBC prediction mode or the palette mode may be used for image / video coding of content such as games, such as screen content coding (SCC). IBC may basically perform a prediction in the current picture, but may be performed similarly to inter prediction so that a reference block is derived within the current picture. That is, IBC may use at least one inter prediction technique described in this document. The palette mode may be considered as an example of intra coding or intra prediction. When the palette mode is applied, information about the palette table and the palette index may be included in the video / image information and signaled.

[0073] The intra-frame predictor 331 can predict the current block by referring to samples in the current picture. Depending on the prediction mode, the referenced sample can be located near the current block or can be separated from the current block. In intra-frame prediction, the prediction mode can include multiple non-directional modes and multiple directional modes. The intra-frame predictor 331 can determine the prediction mode applied to the current block by using the prediction mode applied to the neighboring block.

[0074] The inter-frame predictor 332 may derive a prediction block of the current block based on a reference block (reference sample array) specified by a motion vector on a reference picture. In this case, in order to reduce the amount of motion information sent in the inter-frame prediction mode, the motion information may be predicted in units of blocks, sub-blocks, or samples based on the correlation of the motion information between the adjacent blocks and the current block. The motion information may include a motion vector and a reference picture index. The motion information may also include information about the inter-frame prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.). In the case of inter-frame prediction, the adjacent blocks may include spatial adjacent blocks present in the current picture and temporal adjacent blocks present in the reference picture. For example, the inter-frame predictor 332 may construct a motion information candidate list based on the adjacent blocks and derive the motion vector and / or reference picture index of the current block based on the received candidate selection information. Inter-frame prediction may be performed based on various prediction modes, and information about the prediction may include information indicating the inter-frame prediction mode for the current block.

[0075] The adder 340 can generate a reconstructed signal (reconstructed picture, reconstructed block, reconstructed sample array) by adding the obtained residual signal to the prediction signal (prediction block, prediction sample array) output from the predictor (including the inter-frame predictor 332 and / or the intra-frame predictor 331). If there is no residual for the processing target block, such as when the skip mode is applied, the prediction block can be used as the reconstructed block.

[0076] The adder 340 may be referred to as a reconstructor or a reconstructed block generator. The generated reconstructed signal may be used for intra prediction of the next block to be processed in the current picture, and as described later, may also be output through filtering or may also be used for inter prediction of the next picture.

[0077] In addition, luminance mapping with chroma scaling (LMCS) can also be applied to the picture decoding process.

[0078] The filter 350 can improve the subjective / objective image quality by applying filtering to the reconstructed signal. For example, the filter 350 can generate a modified reconstructed picture by applying various filtering methods to the reconstructed picture, and store the modified reconstructed picture in the memory 360, specifically, in the DPB of the memory 360. The various filtering methods may include, for example, deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, etc.

[0079] The (modified) reconstructed picture stored in the DPB of the memory 360 can be used as a reference picture in the inter-frame predictor 332. The memory 360 can store the motion information of the block from which the motion information in the current picture is derived (decoded) and / or the motion information of the block in the reconstructed picture. The stored motion information can be transmitted to the inter-frame predictor 260 to be used as the motion information of the spatial neighboring block or the motion information of the temporal neighboring block. The memory 360 can store the reconstructed samples of the reconstructed block in the current picture and transmit the reconstructed samples to the intra-frame predictor 331.

[0080] In this document, the embodiments described in the filter 260 , the inter predictor 221 , and the intra predictor 222 of the encoding apparatus 200 may be equally applied to or correspond to the filter 350 , the inter predictor 332 , and the intra predictor 331 .

[0081] At the same time, the video / image coding method according to the present document can be performed based on the following partition structure. Specifically, the above-mentioned prediction, residual processing ((inverse) transform and (de)quantization), syntax element coding and filtering processes can be performed according to the CTU and CU (and / or TU and PU) derived based on the partition structure. The block partitioning process can be performed by the image partitioner 210 of the above-mentioned encoding device, and the partition-related information can be processed (encoded) by the entropy encoder 240 and can be transmitted to the decoding device in the form of a bitstream. The entropy decoder 310 of the decoding device can derive the block partition structure of the current picture based on the partition-related information obtained from the bitstream, and based on this, a series of processes for image decoding (e.g., prediction, residual processing, block / picture reconstruction, loop filtering, etc.) can be performed. The CU size and the TU size can be equal to each other, or multiple TUs can exist within the CU area. At the same time, the CU size can generally represent the brightness component (sample) coding block (CB) size. The TU size can generally represent the brightness component (sample) transform block (TB) size. The chroma component (sample) CB or TB size can be derived based on the luminance component (sample) CB or TB size according to the component ratio according to the color format (chroma format, for example, 4:4:4, 4:2:2, 4:2:0, etc.) of the picture / image. The TU size can be derived based on maxTbSize. For example, if the CU size is larger than maxTbSize, multiple TUs (TBs) of maxTbSize can be derived from the CU, and the transform / inverse transform can be performed in units of TU (TB). In addition, for example, in the case of applying intra-frame prediction, the intra-frame prediction mode / type can be derived in units of CU (or CB), and the neighboring reference sample derivation and prediction sample generation process can be performed in units of TU (or TB). In this case, one or more TUs (or TBs) may exist in one CU (or CB) area, and in this case, multiple TUs (or TBs) may share the same intra-frame prediction mode / type.

[0082] In addition, in the video / image coding according to this document, the image processing unit may have a hierarchical structure. A picture may be partitioned into one or more tiles, tiles, slices and / or tile groups. A slice may include one or more tiles. A tile may include one or more CTU rows within a tile. A slice may include an integer number of blocks of a picture. A tile group may include one or more tiles. A tile may include one or more CTUs. A CTU may be partitioned into one or more CUs. A tile represents a rectangular area of ​​a CTU within a specific tile column and a specific tile row in a picture. According to the tile raster scan in the picture, a tile group may include an integer number of tiles. A slice header may carry information / parameters that can be applied to a corresponding slice (a block in a slice). In the case where the encoding / decoding device has a multi-core processor, the encoding / decoding process of tiles, slices, tiles and / or tile groups may be processed in parallel. In this document, slices or tile groups may be used interchangeably. That is, a tile group header may be referred to as a slice header. Here, the slice may have one of the slice types, including intra (I) slices, predicted (P) slices, and bidirectional predicted (B) slices. When predicting blocks in an I slice, inter prediction may not be used, and only intra prediction may be used. Of course, even in this case, signaling may be performed by coding the original sample values ​​without prediction. With respect to blocks in a P slice, intra prediction or inter prediction may be used, and in the case of using inter prediction, only unidirectional prediction may be used. Meanwhile, with respect to blocks in a B slice, intra prediction or inter prediction may be used, and in the case of using inter prediction, up to bidirectional prediction may be used to the greatest extent.

[0083] The encoding device may determine the patch / patch group, tile, slice, and maximum and minimum coding unit sizes taking into account coding efficiency or parallel processing, or according to characteristics of the video image (e.g., resolution), and information regarding them or information that can induce them may be included in the bitstream.

[0084] The decoding device can obtain information indicating the tiles / tile groups, tiles, and slices of the current picture and whether the CTU in the tiles has been partitioned into multiple coding units. By obtaining (sending) such information only under certain conditions, efficiency can be enhanced.

[0085] At the same time, as described above, a picture may include multiple slices, and a slice may include a slice header and slice data. In this case, a picture header may be further added for multiple slices in a picture (a set of slice headers and slice data). The picture header (picture header syntax) may include information / parameters that can be commonly applied to the picture. The slice header (slice header syntax) may include information / parameters that can be commonly applied to the slice. An adaptive parameter set (APS) or a picture parameter set (PPS) may include information / parameters that can be commonly applied to one or more pictures. A sequence parameter set (SPS) may include information / parameters that can be commonly applied to one or more sequences. A video parameter set (VPS) may include information / parameters that can be commonly applied to multiple layers. A decoding parameter set (DPS) may include information / parameters that can be commonly applied to the overall video. The DPS may include information / parameters related to the concatenation of a coded video sequence (CVS).

[0086] In this document, the high-level syntax may include at least one of an APS syntax, a PPS syntax, an SPS syntax, a VPS syntax, a DPS syntax, a picture header syntax, and a slice header syntax.

[0087] In addition, for example, information about partition and configuration of tiles / tile groups / tiles / slices, etc. may be configured in the encoding device based on a high-level syntax and then be delivered (or transmitted) to the decoding device in a bitstream format.

[0088] A picture can be partitioned into one or more tile rows and one or more tile columns. A tile is a sequence of CTUs covering a rectangular area of ​​a picture. A tile can be partitioned into one or more tiles, and each tile can be configured by multiple CTU rows. A tile that is not partitioned into multiple tiles can also be referred to as a tile. However, a tile that is a subset of a tile is not referred to as a tile. A slice can include multiple tiles or multiple tiles of a tile.

[0089] Figure 4 An example of a picture decoding process is shown.

[0090] In image / video coding, pictures configuring an image / video may be encoded / decoded according to a decoding order. The picture order corresponding to the output order of the decoded pictures may be configured differently from the decoding order. Furthermore, when inter-frame prediction is performed based on the configured picture order, forward prediction as well as backward prediction may be performed.

[0091] Figure 4 A general example of a picture decoding process to which the embodiments of the present disclosure can be applied is shown. Figure 4 In the S400, the Figure 3S400 may include the information decoding process described in this specification, S410 may include the inter / intra prediction process described in this specification, S420 may include the residual processing process described in this specification, S430 may include the block / picture reconstruction process described in this specification, and S440 may include the loop filtering process described in this specification.

[0092] refer to Figure 4 , as above Figure 3 As described in, the picture decoding process may generally include a process (S400) of obtaining image / video information from a bitstream (by decoding), a picture reconstruction process (S410 to S430), and a loop filtering process (S440) for reconstructing the picture. The picture reconstruction process may be performed based on the prediction samples and residual samples obtained by performing the inter / intra prediction process (S410) and the residual processing process (S420, the dequantization and inverse transformation process of the quantized transform coefficients). By performing the loop filtering process on the reconstructed picture generated by performing the picture reconstruction process, a modified reconstructed picture may be generated, and the modified reconstructed picture may be output as a decoded picture, and then stored in the image buffer or memory 360 of the decoding device, so that it is used as a reference image during the inter-frame prediction process when the decoding of the picture is performed in a subsequent process. In some cases, the loop filtering process may be skipped. And, in this case, the reconstructed picture may be output as a decoded picture, and then stored in the decoded picture buffer or memory 360 of the decoding device, so that it is used as a reference picture in the inter-frame prediction process when the decoding of the picture is performed in a subsequent process. As described above, the loop filtering process (S440) may include a deblocking filtering process, a sample adaptive offset (SAO) process, an adaptive loop filter (ALF) process, and / or a bilateral filter process, etc., and some or all of the loop filtering processes may be skipped. In addition, one or part of the deblocking filtering process, the sample adaptive offset (SAO) process, the adaptive loop filter (ALF) process, and the bilateral filter process may be applied sequentially, or all of the deblocking filtering processes, the sample adaptive offset (SAO) process, the adaptive loop filter (ALF) process, and the bilateral filter process may be applied sequentially. For example, after the deblocking filtering process is applied to the reconstructed picture, the SAO process may be performed. Alternatively, for example, after the deblocking filtering process is applied to the reconstructed picture, the ALF process may be performed. This may also be performed similarly in an encoding device.

[0093] Figure 5An example of a picture encoding process is shown.

[0094] Figure 5 A general example of a picture encoding process to which the embodiments of the present disclosure can be applied is shown. Figure 5 In the S500, the Figure 2 S500 may include the inter / intra prediction process described in this specification, S610 may include the residual processing process described in this specification, and S520 may include the information encoding process described in this specification.

[0095] refer to Figure 5 , as above Figure 2 As described in, the image encoding process may generally include a process of encoding information for picture reconstruction (e.g., prediction information, residual information, partition information, etc.) and outputting the encoded information in a bitstream format, as well as a process of generating a reconstructed picture for the current picture and a process of applying loop filtering to the reconstructed picture (optional). The encoding device may derive residual samples (modified) from the quantized transform coefficients through a dequantizer 234 and an inverse transformer 235, and then the encoding device may generate a reconstructed picture based on the prediction samples and (modified) residual samples output as S500. The reconstructed picture generated as described above may be the same as the above-mentioned reconstructed picture generated in the decoding device. The modified reconstructed picture may be generated by performing a loop filtering process on the reconstructed picture, and then stored in a decoded picture buffer or memory 270 of the decoding device. And, just as in the decoding device, when encoding the picture, the modified reconstructed picture may be used as a reference picture during the inter-frame prediction process. As described above, in some cases, part or all of the loop filtering process may be skipped. When a loop filtering process is performed, (loop) filtering related information (parameters) may be encoded in the entropy encoder 240 and then transmitted in a bitstream format, and the decoding device may perform the loop filtering process by using the same method as the encoding device based on the filtering related information.

[0096] By performing the above-mentioned loop filtering process, noise such as blocking artifacts and ringing artifacts that occur when encoding an image / motion picture image can be reduced, and subjective / objective visual quality can be enhanced. In addition, by causing both the encoding device and the decoding device to perform the loop filtering process, the encoding device and the decoding device can derive the same prediction result, increase the reliability of image coding, and reduce the size (or amount) of data that should be sent for image coding.

[0097] As described above, the picture reconstruction process can be performed in a decoding device and an encoding device. A reconstructed block can be generated for each block unit based on intra prediction / inter prediction, and a reconstructed picture including the reconstructed block can be generated. When 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 reconstructed based only on intra prediction. At the same time, when 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 reconstructed based on intra prediction or inter prediction. In this case, inter prediction can be applied to some blocks within the current picture / slice / tile group, and intra prediction can be applied to the remaining blocks. The color components of the picture may include a luminance component and a chrominance component. And, unless explicitly defined (or limited) in this specification, the methods and embodiments proposed in this specification may be applied to luminance components and chrominance components.

[0098] Meanwhile, as described above, high-level syntax (HLS) can be compiled / signaled for video / image coding. A compiled picture can be configured by one or more slices. Parameters describing the compiled picture are signaled in the picture header, and parameters describing the slice are signaled in the slice header. The picture header is carried in its own NAL unit format. And, the slice header is present at the beginning (or starting point) of the NAL unit that includes the payload (i.e., slice data) of the slice.

[0099] Each picture is associated with a picture header. A picture can be configured by different types of slices (intra-coded slices (ie, I slices) and inter-coded slices (ie, P slices and B slices). Therefore, the picture header may include syntax elements required in intra slices of a picture and inter slices of a picture.

[0100] A picture may be partitioned into (or divided into) sub-pictures, tiles, and / or slices. Sub-picture signaling may be present in a sequence parameter set (SPS). And, tile and square slice signaling may be present in a picture parameter set (PPS). Raster scan slice signaling may be present in a slice header.

[0101] For example, regarding partitioning of a picture, syntax elements shown in the following Table 1 may be included in the SPS syntax.

[0102] [Table 1]

[0103]

[0104] The syntax elements shown in Table 2 below may be included in the PPS syntax.

[0105] [Table 2]

[0106]

[0107]

[0108] In Table 2, num_slices_in_tile_minus1[i]+1 indicates the number of slices within the current tile when the i-th slice includes a subset of CTU rows in a single tile. The value of num_slices_in_tile_minus1[i] should be in the range of 0 to RowHeight[tileY]-1, inclusive. Here, tileY is the index of the tile row including the i-th slice. When num_slices_in_tile_minus1[i] does not exist in the PPS, the value of num_slices_in_tile_minus1[i] is derived as 0.

[0109] slice_height_in_ctu_minus1[i]+1 indicates the height of the i-th rectangular slice in units of CTU rows when the i-th slice includes a subset of CTU rows in a single tile. The value of slice_height_in_ctu_minus1[i] should be in the range of 0 to RowHeight[tileY]-1, inclusive. Here, tileY is the index of the tile row that includes the i-th slice.

[0110] The syntax elements shown in the following Table 3 may be included in the slice header syntax.

[0111] [Table 3]

[0112]

[0113] Referring to Tables 1 to 3, in the current tile and slice design, a rectangular slice may include one or more tiles. Alternatively, a rectangular slice may include an integer number (or whole number) of CTU rows within a single tile.

[0114] When a rectangular slice includes an integer (or complete number) of CTU rows within a single tile (which corresponds to the case where the tile is partitioned into two or more slices), in current signaling, the height of each slice is explicitly signaled. However, this type of signaling is not an optimal signaling method.

[0115] The layout of slices within a tile may include a case where the height of the slices within the tile is uniform except for the last slice, and a case where the height of the slices within the tile is not uniform. When the height of the slices within the tile is uniform except for the last slice, since the heights of all slices within the tile excluding the last slice are the same, the height of only one slice may be signaled without explicitly signaling the height of each slice. When the height of the slices within the tile is not uniform, the height of each slice within the tile needs to be signaled.

[0116] The following figures are illustrated to describe detailed examples of this specification. The detailed terms of the devices (or equipment) or the detailed terms of the signals / information specified in the figures are only exemplary. Therefore, the technical features of this specification will not be limited to the detailed terms used in the following figures.

[0117] This specification provides the following methods to solve the above problems. Each method can be applied alone or in combination.

[0118] For example, when a tile includes two or more slices, multiple slice heights that are explicitly signaled within a CTU row can be signaled. This can be referred to as the syntax element num_exp_slice_in_tile. In this case, a syntax element (an array of slice_row_height_minus1) indexed from 0 to num_exp_slice_in_tile-1 can be signaled. This can be signaled as ue(v) or u(v), and the number of bits used to signal such a syntax element can vary depending on the number of CTU rows within the tile. Here, ue(v) represents a syntax element for 0-order exponential Golomb coding, and u(v) indicates that v bits are used, where the value of v varies depending on the values ​​of other syntax elements.

[0119] The height of each slice from the first slice to the nth slice within a tile is given a value of slice_row_height_minus1+1 from 0 to num_exp_slice_in_tile-1, respectively. Here, n is equal to the number of slices within a tile (num_exp_slice_in_tile) that is explicitly signaled.

[0120] New slices are defined within a tile even though there are always more than num_exp_slice_in_tile_minus1+1 and the last (explicitly) signaled remaining CTU rows within the tile. In other words, there are slices within the tile that are not explicitly signaled. The height of the last slice may be equal to or less than the last signaled num_exp_slice_in_tile_minus1+1.

[0121] As another example, when a tile includes two or more slices, the multiple slices included in the tile may be signaled. In this case, a flag indicating whether the height of each slice within the tile is uniform may be signaled. When the height of each slice within the tile is uniform, only one slice height may be signaled per CTU row. The height of each slice within the tile may be derived based on the signaled slice height. And, when the height of each slice within the tile is not uniform, the height of each slice within the tile excluding the last slice may be explicitly signaled.

[0122] In the present specification, information about slices and / or patches may include information and / or syntax elements disclosed in Tables 1 to 3. Image / video information may include high-level syntax (HLS) disclosed in Tables 1 to 3, and the high-level syntax (HLS) may include information related to slices and / or information related to patches. Information related to slices may include information indicating one or more slices within the current picture, and information related to patches may include information indicating one or more patches within the current picture. Patches including one or more slices and slices including one or more patches may exist in a picture.

[0123] As an embodiment, in order to express the partition structure of a picture, the syntax shown in Table 4 and the semantics shown in Table 5 may be used for the PPS.

[0124] [Table 4]

[0125]

[0126] [Table 5]

[0127]

[0128]

[0129] Referring to Tables 4 and 5, num_exp_slices_in_tile[i]+1 represents the number of exp_slice_height_in_ctu_minus1[j] present in the PPS. When num_exp_slices_in_tile[i] does not exist in the PPS, the value of num_exp_slices_in_tile_minus1[i] is derived as 0.

[0130] exp_slice_height_in_ctu_minus1[j]+1 indicates the height of the j-th rectangular slice explicitly signaled in units of CTU rows when the i-th slice includes a subset of CTU rows in a single tile. The value of exp_slice_height_in_ctu_minus1[j] should be in the range of 0 to RowHeight[tileY]-1, inclusive. Here, tileY is the index of the tile row that includes the slice.

[0131] That is, num_exp_slices_in_tile[i] may be referred to as information about the number of slices whose heights are explicitly signaled within the tile of the current picture (quantity information), and exp_slice_height_in_ctu_minus1[j] may be referred to as information about the height of each slice whose height is explicitly signaled (height information).

[0132] The quantity information and the height information may be syntax elements of the Exponential Golomb compilation.

[0133] The quantity information may be parsed based on information about the width and height of the slice including the patch. When the patch includes an i-th slice, the width information of the slice including the patch may correspond to the syntax element slice_width_in_tiles_minus1[i], and the height information of the slice including the patch may correspond to the syntax element slice_height_in_tiles_minus1[i]. The i-th slice may be a rectangular slice, and the slices within the patch may also be partitioned into rectangular slices.

[0134] For example, the encoding device may generate the quantity information and the height information based on the information about the slice of the current picture. The quantity information and the height information may be included in the image information and signaled to the decoding device in a bitstream format.

[0135] When parsing the quantity information from the PPS, as shown in Table 4, the decoding device may parse the height information from the PPS based on the quantity information. For example, when the value of the quantity information is equal to n (where n is an integer equal to or greater than 0), the decoding device may parse the height information about n slices (starting from the 0th slice to the (n-1)th slice within the tile) from the PPS. The height information may indicate each of the height of the 0th slice to the height of the (n-1)th slice in the coding tree unit (CTU) row.

[0136] Thereafter, the decoding device may derive the height of the remaining slices within the patch based on the height of the (n-1)th slice. More specifically, the decoding device may derive the height of the remaining slices within the patch excluding the last slice starting from the nth slice within the patch to be equal to the height of the (n-1)th slice. To this end, the decoding device may compare the remaining height of the patch, which is calculated by subtracting the sum of the heights of the slices starting from the 0th slice to the (n-1)th slice from the total height of the patch, so as to determine whether the remaining height is equal to or greater than the uniform slice height. Here, a uniform slice may mean a slice having a uniform height (same height) within the patch. That is, the height of the uniform slice may be the same as the height of the (n-1)th slice.

[0137] When the remaining height of the mosaic is equal to or greater than the height of the unified slice, the height of the nth slice can be derived as the height of the unified slice. And, when the remaining height of the mosaic is less than the height of the unified slice, the height of the nth slice can be derived as the remaining height. In addition, when the remaining height of the mosaic is equal to or greater than the height of the unified slice, the updated remaining height can be derived by subtracting the height of the nth slice from the remaining height. And, when the updated remaining height is equal to or greater than the height of the unified slice, the decoding device can derive the height of the (n+1)th slice as the height of the unified slice. When the updated remaining height is less than the height of the unified slice, the decoding device can derive the height of the height of the (n+1)th slice as the updated remaining height. That is, excluding the last slice in the mosaic, the heights of the slices starting from the nth slice to the last slice can be derived as the unified height. The height of the last slice can be equal to or less than the height of each unified slice (starting from the (n-1)th slice to the slice immediately before the last slice).

[0138] For example, when 5 slices are included in one tile, and when the number information indicates 3, height information of the first to third slices within the tile may be parsed from the PPS, and the height of the fourth slice within the tile may be derived to have the same height as the third slice. In this case, the height of the fifth slice may be greater than or less than the height of the fourth slice.

[0139] The decoding device can derive the number of slices within the patch by performing the above scanning process. When the value of the quantity information is greater than 0, the process of deriving information about the height of each slice within the patch and information about the number of slices within the patch can be instructed, as shown in Table 5 below.

[0140] [Table 6]

[0141]

[0142] In the case of rectangular slices, the list NumCtuInSlice[i] including i in the range of 0 to num_slices_in_pic_minus1 may indicate the number of CTUs within the i-th slice, the matrix CtbAddrInSlice[i][j] including i in the range of 0 to num_slices_in_pic_minus1 and j in the range of 0 to NumCtuInSlice[i]-1 indicates the picture raster scan addressing of the j-th CTB within the i-th slice, and may be derived as shown in Table 7 below.

[0143] [Table 7]

[0144]

[0145] As another embodiment, in order to express the partition structure of a picture, the syntax shown in Table 8 and the semantics shown in Table 9 may be used for the PPS.

[0146] [Table 8]

[0147]

[0148] [Table 9]

[0149]

[0150]

[0151] Referring to Tables 8 and 9, if the value of uniform_slice_spacing_flag[i] is equal to 1, this indicates that the CTU row is uniformly distributed (or dispersed) throughout the tile, and is signaled by using the syntax element uniform_slice_height_in_ctu_minus1[i]. If the value of uniform_slice_spacing_flag[i] is equal to 0, this indicates that the CTU row may or may not be uniformly distributed (or dispersed) throughout the tile, and is signaled by using the syntax elements num_slices_in_tile_minus1[i] and slice_height_in_ctu_minus1[i].

[0152] When the value of uniform_slice_spacing_flag[i] is equal to 1, slice_rows_height_in_ctu_minus1[i]+1 indicates the height of the slice excluding the last slice of the tile in units of CTBs. The value of slice_height_in_ctu_minus1[i] should be in the range of 0 to RowHeight[tileY]-1, inclusive. Here, tileY is the index of the tile row that includes the slice.

[0153] num_slices_in_tile_minus1[i]+1 indicates the number of slices within the current slice when the i-th slice includes a subset of CTU rows in a single tile and when the value of uniform_slice_spacing_flag[i] is equal to 0. The value of num_slices_in_tile_minus1[i] should be in the range of 0 to RowHeight[tileY]-1, inclusive. Here, tileY is the index of the tile row that includes the i-th slice. When num_slices_in_tile_minus1[i] does not exist, the value of num_slices_in_tile_minus1[i] is derived as 0.

[0154] slice_height_in_ctu_minus1[i]+1 indicates the height of the i-th rectangular slice in units of CTU rows when the i-th slice includes a subset of CTU rows in a single tile. The value of slice_height_in_ctu_minus1[i] should be in the range of 0 to RowHeight[tileY]-1, inclusive. Here, tileY is the index of the tile row that includes the i-th slice.

[0155] For example, the encoding apparatus may generate at least one of uniform_slice_spacing_flag, slice_rows_height_in_ctu_minus1, num_slices_in_tile_minus1, and slice_height_in_ctu_minus1 based on information about the slice of the current picture.

[0156] When parsing the uniform_slice_spacing_flag from the PPS, as shown in Table 8, the decoding device may parse slice_rows_height_in_ctu_minus1 or num_slices_in_tile_minus1 from the PPS based on the value of the uniform_slice_spacing_flag. For example, if the value of the uniform_slice_spacing_flag is equal to 1, the decoding device may parse slice_rows_height_in_ctu_minus1 from the PPS, and then may export the parsing result as the height of the remaining slices excluding the last slice within the tile based on the value of slice_rows_height_in_ctu_minus1. If the value of the uniform_slice_spacing_flag is equal to 0, the decoding device may parse num_slices_in_tile_minus1 and slice_height_in_ctu_minus1 from the PPS, and may export the slices within the tile based on the parsed results.

[0157] For example, variables NumSlicesInTileMinus1[i] and SliceHeightInCtuMinus1[i + k] related to the number information and height information of the slices within the tile may be derived as follows. Here, k may range from 0 to NumSlicesInTileMinus1[i].

[0158] [Table 10]

[0159]

[0160] In the case of rectangular slices, the list NumCtuInSlice[i] for i in the range from 0 to num_slices_in_pic_minus1 may indicate the number of CTUs within the i-th slice, and the matrix CtbAddrInSlice[i][j] for i in the range from 0 to num_slices_in_pic_minus1 and j in the range from 0 to NumCtuInSlice[i] - 1 may indicate the picture raster scan addressing of the j-th CTB within the i-th slice, and may be derived as shown in Table 11 below.

[0161] [Table 11]

[0162]

[0163] Figure 6 and Figure 7General examples of video / image encoding methods and related components according to embodiments of the present disclosure are respectively shown.

[0164] Figure 6 The video / image encoding method disclosed in Figure 2 and Figure 7 The (video / image) encoding device 200 disclosed in is executed. More specifically, for example, Figure 6 S600 may be performed by the image partitioner 210 of the encoding apparatus 200 , and S610 and S620 may be performed by the entropy encoder 240 of the encoding apparatus 200 . Figure 6 The disclosed video / image encoding method may include the embodiments described above in this specification.

[0165] More specifically, refer to Figure 6 and Figure 7 , the image partitioner 210 of the encoding device can derive a slice within a mosaic of the current picture (S600). For example, the image partitioner 210 can partition an input image (or picture, frame) into one or more CUs. The input image may include one or more pictures. The picture may be partitioned into one or more mosaics, tiles, slices and / or mosaic groups. The slice may include one or more tiles, mosaics and / or mosaic groups. The tile may include one or more CTU rows. The mosaic group may include one or more mosaics. The mosaic may include one or more CTUs. The CTU may be partitioned into one or more CUs. When a specific slice within the current picture is a rectangular slice, the image partitioner 210 may partition the rectangular slice into a plurality of mosaics, and among the plurality of mosaics, the image partitioner 210 may partition at least one mosaic, and then derive a plurality of rectangular slices.

[0166] The predictor 220 of the encoding device may perform prediction on the current block, and then may generate a prediction sample (prediction block) of the current block. The predictor 220 may determine whether intra prediction is being applied or whether inter prediction is being applied in units of the current block or CU. The predictor 220 may generate various information related to the prediction (prediction related information) and deliver the generated prediction related information to the entropy encoder 240. Here, the prediction related information may include information related to the inter prediction mode and information related to the intra prediction mode. When the prediction mode of the current block is the inter prediction mode, the prediction sample may be generated in the inter predictor 221 of the predictor 220. And, when the prediction mode of the current block is the intra prediction mode, the prediction sample may be generated in the intra predictor 222 of the predictor 220.

[0167] The residual processor 230 of the encoding device may generate residual samples and residual information based on the prediction samples generated from the predictor 220 and the original picture (original block, original sample). Here, the residual information is information related to the residual samples, and the residual information may include information related to the (quantized) transform coefficients of the residual samples.

[0168] The adder (or reconstructor) of the encoding device can generate reconstructed samples (reconstructed pictures, reconstructed blocks, reconstructed sample arrays) by adding the residual samples generated in the residual processor 230 and the prediction samples generated in the inter-frame predictor 221 or the intra-frame predictor 222.

[0169] The entropy encoder 240 of the encoding device may generate information related to the partition based on the partition structure derived in the image partitioner 210. The partition related information may include information about the number of slices whose each slice height is explicitly signaled within the tile (quantity information), and information about the height of the slice whose each slice height is explicitly signaled (height information). For example, the entropy encoder 240 may generate quantity information related to the number of slices whose each slice height is explicitly signaled (provided) within the tile, and height information related to the height of the slice whose each slice height is explicitly signaled (provided) based on the slices derived in the image partitioner 210 (S610). Here, the quantity information may include the above-mentioned syntax elements num_exp_slices_in_tile and / or num_slices_in_tile_minus1. The height information may include the above-mentioned syntax elements exp_slice_height_in_ctu_minus1, slice_rows_height_in_ctu_minus1 and / or slice_height_in_ctu_minus1.

[0170] The entropy encoder 240 may encode the image information including the partition-related information including the quantity information and the height information, the prediction-related information generated in the predictor 220, and / or the residual information generated in the residual processor 230 (S620). The information encoded in the entropy encoder 240 may be output in a bitstream format. The bitstream may be transmitted to a decoding device via a network or a storage medium.

[0171] For example, the entropy encoder 240 may include image information including a syntax element num_exp_slices_in_tile as quantity information and a syntax element exp_slice_height_in_ctu_minus1 as height information based on Tables 4 and 5 above. The height information may indicate the height of a slice whose each slice height is explicitly signaled within a tile in units of CTU rows, and for this purpose, the height information may include a syntax element for a slice whose each slice height is explicitly signaled. The number of syntax elements included in the image information may be the same as the value of the quantity information.

[0172] As another example, the entropy encoder 240 may encode the image information including the syntax elements uniform_slice_spacing_flag, num_slices_in_tile_minus1, slice_rows_height_in_ctu_minus1, and / or slice_height_in_ctu_minus1 based on Tables 8 and 9. The syntax elements num_slices_in_tile_minus1, slice_rows_height_in_ctu_minus1, and slice_height_in_ctu_minus1 may or may not be included in the image information based on the uniform_slice_spacing_flag value.

[0173] The entropy encoder 240 may signal the amount information and the height information through a picture parameter set (PPS) within the image information. In this case, the entropy encoder 240 may include the amount information and / or the height information by using an exponential Golomb method.

[0174] Figure 8 and Fig. 9 General examples of video / image decoding methods and related components according to embodiments of the present disclosure are respectively shown.

[0175] Figure 8 The video / image decoding method disclosed in Figure 3 and Fig. 9 The (video / image) decoding device 300 disclosed in is executed. More specifically, for example, Figure 8 S800 to S830 may be performed by the entropy decoder 310 of the decoding device 300, and Figure 8 S840 may be performed by the residual processor 320 , the predictor 330 , and the adder 340 . Figure 8 The video / image decoding method disclosed in the disclosure may include the embodiments described above in this specification.

[0176] refer to Figure 8 and Fig. 9 , the entropy decoder 310 of the decoding device may obtain partition related information, residual information, prediction related information (inter / intra prediction difference information, intra prediction mode information, inter prediction mode information, etc.), in-loop filtering related information, etc. from the bitstream. Here, the partition related information may include information about the number of slices whose slice heights are explicitly signaled among the slices within the patch of the current picture (number information), information about the height of the slice whose slice heights are explicitly signaled (height information), etc.

[0177] For example, the entropy decoder 310 may parse information related to the number of slices whose heights are explicitly signaled among the slices within the patch of the current picture (quantity information) (S800), and may parse information related to the height of the slices whose heights are explicitly signaled (height information) (S810) from the bitstream based on the quantity information. More specifically, the entropy decoder 310 may parse quantity information and height information from a picture parameter set (PPS) of the bitstream based on Table 4 above. Here, the quantity information may be parsed based on information about the width and height of the slices including the patch. At this time, the slices including the patch and / or the slices within the patch may be rectangular slices. The quantity information and the height information may be syntax elements of exponential Golomb coding. The height information may include syntax elements for slices whose heights are explicitly signaled. The number of syntax elements may be the same as the quantity information value.

[0178] For example, the entropy decoder 310 may parse the syntax elements slice_width_in_tiles_minus1 and slice_height_in_tiles_minus1 from the picture parameter set (PPS) based on Table 4, and the entropy decoder 310 may parse the syntax element num_exp_slices_in_tile from the picture parameter set (PPS) based on the values ​​of the syntax elements slice_width_in_tiles_minus1 and slice_height_in_tiles_minus1. Also, the entropy decoder 310 may parse the same number of exp_slice_height_in_ctu_minus1 as the value of the syntax element num_exp_slices_in_tile from the picture parameter set (PPS).

[0179] When the value of the quantity information is equal to n, the entropy decoder 310 may derive the heights of the 0th slice to the (n-1)th slice within the patch based on the height information (S820). Furthermore, the entropy decoder 310 may derive the height of the nth slice within the patch based on the height of the (n-1)th slice (S830). That is, the height of the nth slice may be derived to be the same as the height of the (n-1)th slice. Here, the nth slice may not be the last slice within the patch. In other words, the entropy decoder 310 may derive that the heights of the remaining slices (slices not explicitly signaled) excluding the last slice within the patch have the same height as the (n-1)th slice. Therefore, the heights of the slices starting from the nth slice within the patch to the last slice may be uniform except for the last slice within the patch. The entropy decoder 310 may derive the height of the last slice within the patch based on the remaining height after subtracting the heights of the other slices within the patch from the height of the patch (S840). When the heights of all slices within the patch are derived, the entropy decoder 310 may derive the number of slices within the patch (S850). Here, the number of slices within the tile may correspond to the number of slices starting from the 0th slice to the last slice within the tile.

[0180] The decoding device 300 may decode the current picture based on the slice of the current picture derived by performing the above process (S860). More specifically, the residual processor 320 of the decoding device may generate residual samples based on the residual information obtained from the entropy decoder 310. The predictor 330 of the decoding device may perform inter-frame prediction and / or intra-frame prediction based on the prediction-related information obtained from the entropy decoder 310 so as to generate prediction samples. The adder 340 of the decoding device may generate reconstructed samples based on the prediction samples generated in the predictor 330 and the residual samples generated in the residual processor 320. And, the adder 340 of the decoding device may generate a reconstructed picture (reconstructed block) based on the reconstructed samples.

[0181] Thereafter, a loop filtering process such as deblocking filtering, SAO and / or ALF process may be applied to the reconstructed picture as needed in order to enhance the subjective / objective picture quality.

[0182] Meanwhile, as another example, the entropy decoder 310 may parse the syntax elements slice_width_in_tiles_minus1 and slice_height_in_tiles_minus1 from the picture parameter set (PPS) of the bitstream based on Table 8, and the entropy decoder 310 may parse the syntax element uniform_slice_spacing_flag from the picture parameter set (PPS) based on the values ​​of the syntax elements slice_width_in_tiles_minus1 and slice_height_in_tiles_minus1. In this case, the entropy decoder 310 may parse the syntax element slice_rows_height_in_ctu_minus1 or parse the syntax element num_slices_in_tile_minus1 from the picture parameter set (PPS) based on the value of the syntax element uniform_slice_spacing_flag. When the value of the syntax element uniform_slice_spacing_flag is equal to 1, the syntax element slice_rows_height_in_ctu_minus1 may be parsed, and when the value of the syntax element uniform_slice_spacing_flag is equal to 0, the syntax element num_slices_in_tile_minus1 may be parsed.

[0183] When the syntax element slice_rows_height_in_ctu_minus1 is parsed, the entropy decoder 310 may derive the heights of the remaining slices excluding the last slice within the tile as the value of slice_rows_height_in_ctu_minus1.

[0184] When parsing the syntax element num_slices_in_tile_minus1, the entropy decoder 310 may parse the number of syntax elements slice_height_in_ctu_minus1 corresponding to the value of the syntax element num_slices_in_tile_minus1, and may derive these values ​​as the height of each slice within the tile, respectively.

[0185] Although the method has been described based on a flowchart in which steps or boxes are listed in sequence in the above-mentioned embodiments, the steps of the present disclosure are not limited to a specific order, and a certain step may be performed in a different step or in a different order or simultaneously relative to the above-mentioned order. In addition, it should be understood by a person of ordinary skill in the art that the steps in the flowchart are not exclusive, and another step may be included therein or one or more steps in the flowchart may be deleted without affecting the scope of the present disclosure.

[0186] The above-mentioned method according to the present disclosure may be in the form of software, and the encoding device and / or decoding device according to the present disclosure may be included in a device for performing image processing (e.g., TV, computer, smart phone, set-top box, display device, etc.).

[0187] When the embodiments of the present disclosure are implemented by software, the above-mentioned methods can be implemented by modules (processing or functions) that perform the above-mentioned functions. The module can be stored in a memory and executed by a processor. The memory can be installed inside or outside the processor and can be connected to the processor via various well-known devices. The processor may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits and / or data processing devices. The memory may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium and / or other storage devices. In other words, according to the embodiments of the present disclosure, it can be implemented and executed on a processor, a microprocessor, a controller or a chip. For example, the functional units illustrated in the corresponding figures can be implemented and executed on a computer, a processor, a microprocessor, a controller or a chip. In this case, information about the implementation (e.g., information about instructions) or an algorithm can be stored in a digital storage medium.

[0188] In addition, the decoding device and encoding device of the embodiment of the present disclosure can be included in a multimedia broadcast transceiver, a mobile communication terminal, a home theater video device, a digital theater video device, a surveillance camera, a video chat device, a real-time communication device such as video communication, a mobile streaming device, a storage medium, a portable camera, a video on demand (VoD) service provider, an over-the-top (OTT) video device, an Internet streaming service provider, a 3D video device, a virtual reality (VR) device, an augmented reality (AR) device, an image phone video device, a vehicle terminal (e.g., a vehicle (including an autonomous vehicle) terminal, an aircraft terminal or a ship terminal) and a medical video device; and can be used to process image signals or data. For example, an OTT video device may include a game console, a Blueray player, a networked TV, a home theater system, a smart phone, a tablet PC, and a digital video recorder (DVR).

[0189] In addition, the processing method of the embodiment of the present disclosure can be generated in the form of a program executed by a computer and can be stored in a computer-readable recording medium. The multimedia data with a data structure according to the embodiment of the present disclosure can also be stored in a computer-readable recording medium. The computer-readable recording medium includes all kinds of storage devices and distributed storage devices storing computer-readable data. The computer-readable recording medium may include, for example, a Blu-ray disc (BD), a universal serial bus (USB), a ROM, a PROM, an EPROM, an EEPROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device. The computer-readable recording medium also includes a medium implemented in the form of a carrier wave (e.g., transmission on the Internet). In addition, the bit stream generated by the encoding method can be stored in a computer-readable recording medium, or can be transmitted through a wired or wireless communication network.

[0190] In addition, the embodiments of the present disclosure can be implemented as a computer program product based on a program code, and the program code can be executed on a computer according to the embodiments of this document. The program code can be stored on a computer readable carrier.

[0191] Fig.10 An example of a content streaming system to which embodiments of this document can be applied is shown.

[0192] refer to Fig.10 A content streaming system to which the embodiments of this document are applied may generally include an encoding server, a streaming server, a web server, a media storage, a user device, and a multimedia input device.

[0193] The encoding server is used to compress the content input from the multimedia input device such as a smart phone, a camera, a camcorder, etc. into digital data, generate a bit stream, and transmit it to the streaming server. As another example, in the case where the multimedia input device such as a smart phone, a camera, a camcorder, etc. directly generates a bit stream, the encoding server can be omitted.

[0194] The bitstream may be generated by the encoding method or the bitstream generation method to which the embodiment of the present disclosure is applied, and the streaming server may temporarily store the bitstream in the process of transmitting or receiving the bitstream.

[0195] The streaming server transmits multimedia data to the user device through the web server based on the user's request, and the web server acts as a tool to inform the user of what services exist. When the user requests the service the user wants, the web server transfers the request to the streaming server, and the streaming server transmits the multimedia data to the user. In this regard, the content streaming system may include a separate control server, and in this case, the control server is used to control the commands / responses between the various devices in the content streaming system.

[0196] The streaming server may receive content from a media storage and / or encoding server. For example, in the case where content is received from an encoding server, the content may be received in real time. In this case, the streaming server may store the bitstream for a predetermined period of time to provide a streaming service smoothly.

[0197] For example, user devices may include mobile phones, smart phones, laptop computers, digital broadcast terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), navigation, tablet PCs, tablet PCs, ultrabooks, wearable devices (e.g., watch-type terminals (smart watches), glasses-type terminals (smart glasses), head-mounted displays (HMDs)), digital TVs, desktop computers, digital signage, etc.

[0198] Each server in the content streaming system may be operated as a distributed server, and in this case, data received by each server may be processed in a distributed manner.

Claims

1. A video decoding method performed by a video decoding device, the method include: parsing from the bitstream information about the number of slices within the tile of the current picture whose height is explicitly signaled; parsing, based on the quantity information, height information related to a height of the slice whose height is explicitly signaled from the bitstream; Based on the number of slices whose heights are explicitly signaled being equal to n, deriving the heights of the 0th slice to the (n-1)th slice within the tile based on the height information; deriving the height of the nth slice within the tile based on the height of the (n-1)th slice; deriving a height of a last slice within the tile based on a remaining height after subtracting heights of other slices within the tile from the height of the tile; deriving the number of slices within the tile; and decoding the current picture based on the slice of the current picture, The analysis of the height information is not performed for the nth slice to the last slice.

2. The video decoding method according to claim 1, in, The number of slices within the tile is equal to the number of slices starting from the 0th slice to the last slice.

3. The video decoding method according to claim 1, in, The height of the nth slice is derived to be the same as the height of the (n-1)th slice.

4. The video decoding method according to claim 1, in, The heights of the slices starting from the nth slice to the slice immediately before the last slice within the tile are uniform.

5. The video decoding method according to claim 4, in, The height of the last slice is less than or equal to the height of the (n-1)th slice.

6. The video decoding method according to claim 1, further comprising: include: comparing a remaining height of the tile calculated by subtracting the sum of the heights of slices starting from the 0th slice to the (n-1)th slice from the total height of the tile to determine whether the remaining height is equal to or greater than the height of a uniform slice, The height of the unified slice is the same as the height of the (n-1)th slice. wherein, based on the remaining height of the tile calculated by subtracting the sum of the heights of the slices starting from the 0th slice to the (n-1)th slice from the total height of the tile being equal to or greater than the height of the uniform slice, the nth slice having the height of the uniform slice is derived, and Wherein, based on the fact that the remaining height of the patch calculated by subtracting the sum of the heights of slices starting from the 0th slice to the (n-1)th slice from the total height of the patch is less than the height of the uniform slice, the nth slice having the remaining height is derived.

7. The video decoding method according to claim 6, in, Based on the remaining height being equal to or greater than the height of the uniform slice, deriving an updated remaining height, wherein the updated remaining height is updated by subtracting the height of the nth slice from the remaining height of the tile, wherein the remaining height is calculated by subtracting the sum of the heights of the slices starting from the 0th slice to the (n-1)th slice from the total height of the tile, wherein, based on the updated remaining height being equal to or greater than the height of the uniform slice, an (n+1)th slice having the height of the uniform slice is derived, and Wherein, based on the fact that the updated remaining height is smaller than the height of the uniform slice, the (n+1)th slice having the updated remaining height is derived.

8. The video decoding method according to claim 1, in, The quantity information and the height information include syntax elements of Exponential Golomb coding.

9. The video decoding method according to claim 1, in, The quantity information comprises a syntax element num_exp_slices_in_tile, and The height information includes the syntax element exp_slice_height_in_ctu_minus1.

10. The video decoding method according to claim 1, in, The slices within the tile are rectangular slices.

11. The video decoding method according to claim 1, in, The quantity information is parsed based on information related to a width and a height of a slice comprising the tile.

12. A video encoding method performed by a video encoding device, the method include: Export slices within the tile of the current image; generating quantity information related to the number of slices within the tile whose heights are explicitly signaled and height information related to the heights of the slices whose heights are explicitly signaled; and encoding the image information including the quantity information and the height information, wherein the number of slices whose heights are explicitly signaled is equal to n, the height information indicates the heights of the 0th slice to the (n-1)th slice within the tile, and Wherein, based on the height of the (n-1)th slice, represents the height of the nth slice in the tile, wherein the height of the last slice in the tile is derived based on the remaining height after subtracting the heights of the other slices in the tile from the height of the tile, and The encoding of the height information is not performed for the nth slice to the last slice.

13. A data transmission method for video, the method include: Obtaining a bitstream for the video, wherein the bitstream is generated based on: deriving slices within a patch of a current picture; generating quantity information related to the number of slices within the patch whose heights are explicitly signaled and height information related to the heights of the slices whose heights are explicitly signaled; and encoding image information including the quantity information and the height information; and sending said data comprising said bit stream, wherein the number of slices whose heights are explicitly signaled is equal to n, the height information indicates the heights of the 0th slice to the (n-1)th slice within the tile, and Wherein, based on the height of the (n-1)th slice, represents the height of the nth slice in the tile, wherein the height of the last slice in the tile is derived based on the remaining height after subtracting the heights of the other slices in the tile from the height of the tile, and The encoding of the height information is not performed for the nth slice to the last slice.

Images