Image / video encoding / decoding method and apparatus

Abstract

The present invention relates to an image / video encoding / decoding method and apparatus. A video decoding method performed according to a video decoding apparatus of the present document may comprise: parsing, from a bitstream, number information highly related to explicitly signaled for a slice in a tile of a current picture; parsing, from the bitstream, height information relating to an explicitly signaled height for slicing, on the basis of the number information; deriving heights of 0th to (n-1) th slices in the tile based on the height information; deriving the height of the nth slice in the tile based on the height of the (n-1) th slice; a height of a last slice in the tile is derived based on the remaining heights.

Description

[0001] This application is a divisional application of the patent application with the application number 202080090689.5 (PCT / KR2020 / 016886), international filing date of November 26, 2020, and invention title of "Image / Video Encoding / Decoding Method and Apparatus", which was filed on June 28, 2022. Technical Field

[0002] The present disclosure relates to a method and apparatus for encoding / decoding an image / video. Background Art

[0003] Recently, the demand for high-resolution, high-quality images / videos such as 4K or 8K or higher ultra-high definition (UHD) images / videos has been increasing in various fields. As the resolution or quality of images / videos becomes higher, a relatively larger amount of information or bits is transmitted compared to conventional image / video data. Therefore, if image / video data is transmitted via a medium such as an existing wired / wireless broadband line or stored in a conventional storage medium, it is likely to increase the costs for transmission and storage.

[0004] In addition, the interest and demand for virtual reality (VR) and artificial reality (AR) content, as well as immersive media such as holograms, are increasing; and the broadcasting of images / videos (e.g., game images / videos) that exhibit image / video characteristics different from actual images / videos is also increasing.

[0005] Therefore, highly efficient image / video compression techniques are needed to effectively compress and transmit, store, or play the high-resolution, high-quality images / videos that exhibit various characteristics as described above. Summary of the Invention

[0006] Technical Problem

[0007] The technical object of the present disclosure is to provide a method and apparatus for increasing the compilation efficiency of an image / video.

[0008] Another technical object of the present disclosure is to provide a method and apparatus for effectively signaling information about slices within a tile.

[0009] Yet another technical object 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.

[0010] Technical Solution

[0011] According to an embodiment of the present specification, there is provided a video decoding method executed by a video decoding device. The method may include the following steps: parsing, from a bitstream, quantity information related to the number of slices in a tile of a current picture whose height of each slice is explicitly signaled; parsing, based on the quantity information, from the bitstream, height information related to the height of each slice whose height is explicitly signaled; based on the value of the quantity information being equal to n, deriving the heights of the 0th slice to the (n - 1)th slice in the tile based on the height information; deriving the height of the nth slice in the tile based on the height of the (n - 1)th slice; deriving the height of the last slice in the tile based on the remaining height after subtracting the heights of other slices in the tile from the height of the tile; deriving the number of slices in the tile; and decoding the current picture based on the slices of the current picture.

[0012] According to another embodiment of the present specification, there is provided a video encoding method executed by a video encoding device. The method may include the following steps: deriving slices in a tile of a current picture; generating, based on the derived slices, quantity information related to the number of slices in the tile whose height of each slice is explicitly signaled and height information related to the height of each slice whose height is explicitly signaled; and encoding image information including the quantity information and the height information, wherein, based on the value of the quantity information being equal to n, the height information may indicate the heights of the 0th slice to the (n - 1)th slice in the tile, and wherein the height of the nth slice in the tile is derived based on the height of the (n - 1)th slice.

[0013] According to still another embodiment of the present specification, there is provided a computer-readable digital recording medium 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, from image information, quantity information related to the number of slices in a tile of a current picture whose height of each slice is explicitly signaled; parsing, based on the quantity information, from the image information, height information related to the height of each slice whose height is explicitly signaled; based on the value of the quantity information being equal to n, deriving the heights of the 0th slice to the (n - 1)th slice in the tile based on the height information; deriving the height of the nth slice in the tile based on the height of the (n - 1)th slice; deriving the height of the last slice in the tile based on the remaining height after subtracting the heights of other slices in the tile from the height of the tile; deriving the number of slices in the tile; and decoding the current picture based on the slices of the current picture.

[0014] Beneficial effects

[0015] According to an embodiment of the present disclosure, the overall compression efficiency of an image / video can be enhanced.

[0016] According to embodiments of the present disclosure, information about slices within a tile can be effectively signaled.

[0017] According to embodiments of the present disclosure, when delivering (or transmitting) information about slices within a tile, signaling overhead can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 An example of a video / image compilation system to which embodiments of the present disclosure can be applied is schematically illustrated.

[0019] Figure 2 is a diagram schematically illustrating the configuration of a video / image encoding device to which embodiments of the present disclosure can be applied.

[0020] Figure 3 is a diagram schematically illustrating the configuration of a video / image decoding device to which embodiments of the present disclosure can be applied.

[0021] Figure 4 An example of a picture decoding process is shown.

[0022] Figure 5 An example of a picture encoding process is shown.

[0023] Figure 6 and Figure 7 respectively show general examples of a video / image encoding method and related components according to embodiments of the present disclosure.

[0024] Figure 8 and Figure 9 respectively show general examples of a video / image decoding method and related components according to embodiments of the present disclosure.

[0025] Figure 10 An example of a content streaming system to which embodiments of the present disclosure can be applied is shown. DETAILED DESCRIPTION

[0026] The disclosure of the present disclosure can be modified in various forms, and its specific embodiments will be described and illustrated in the drawings. The terms used in the present disclosure are only used to describe specific embodiments and are not intended to limit the methods disclosed in the present disclosure. Singular expressions include the expression "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 thus 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.

[0027] 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 mutually different hardware or different software. For example, two or more configurations can be combined to form one configuration, and one configuration can also be divided into multiple configurations. Embodiments of combining and / or separating configurations are included within the scope of the disclosure of this disclosure without departing from the gist of the disclosed method of this disclosure.

[0028] In this document, the terms " / " and "," should be interpreted as indicating "and / or". For example, the expression "A / B" can mean "A and / or B". In addition, "A, B" can mean "A and / or B". In addition, "A / B / C" can mean "at least one of A, B, and / or C". In addition, "A / B / C" can mean "at least one of A, B, and / or C".

[0029] In addition, in the document, the term "or" should be interpreted as indicating "and / or". For example, the expression "A or B" can 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".

[0030] In addition, the parentheses used in this specification can mean "for example". Specifically, in the case of the expression "prediction (intra prediction)", it can indicate that "intra prediction" is presented as an example of "prediction". In other words, the term "prediction" in this specification is not limited to "intra prediction", and can indicate that "intra prediction" is presented as an example of "prediction". In addition, even in the case of the expression "prediction (i.e., intra prediction)", it can also indicate that "intra prediction" is presented as an example of "prediction".

[0031] In this document, the technical features separately explained in one drawing can be implemented separately or simultaneously.

[0032] Hereinafter, embodiments of this document will be described in detail with reference to the drawings. In addition, in all the drawings, the same reference numerals can be used to indicate the same elements, and the same description of the same elements will be omitted.

[0033] Figure 1 An example of a video / image compilation system to which embodiments of this disclosure can be applied is illustrated.

[0034] Refer to Figure 1 , the video / image compilation system can include a first device (source device) and a second device (receiving device). The source device can send the encoded video / image information or data in the form of a file or a stream to the receiving device through a digital storage medium or a network.

[0035] 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.

[0036] The video source may obtain video / images through processes such as capturing, synthesizing, or generating video / images. The video source may include a video / image capturing device and / or a video / image generating device. For example, the video / image capturing device may include one or more cameras, a video / image archive including previously captured video / images, etc. For example, the video / image generating device may include a computer, a tablet computer, and a smart phone, and may (electronically) generate video / images. For example, virtual video / images may be generated by a computer or the like. In this case, the video / image capturing process may be replaced by a process of generating relevant data.

[0037] The encoding device may encode the input video / images. For compression and compilation efficiency, the encoding device may perform a series of processes such as prediction, transformation, and quantization. The encoded data (encoded video / image information) may be output in the form of a bitstream.

[0038] The transmitter may send the encoded image / image information or data output in the form of a bitstream to the receiver of the receiving device in the form of a file or a 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 elements for generating a media file in a predetermined file format and may include elements for transmitting through a broadcast / communication network. The receiver may receive / extract the bitstream and send the received bitstream to the decoding device.

[0039] The decoding device may decode the video / images by performing a series of processes such as dequantization, inverse transformation, and prediction corresponding to the operations of the encoding device.

[0040] The renderer may render the decoded video / images. The rendered video / images may be displayed through a display.

[0041] 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 Essential 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.).

[0042] Various embodiments related to video / image coding are presented in this document, and the embodiments can be combined with each other unless otherwise stated.

[0043] In this document, video may refer to a series of images over a period of time. A picture generally refers to a unit representing an image at a specific time frame, and a slice / tile refers to a unit that forms part of a picture in terms of coding. A slice / tile can include one or more Coding Tree Units (CTUs). A picture can be composed of one or more slices / tiles. A picture can be composed of one or more tile groups. A tile group can include one or more tiles. A brick can represent a rectangular region of CTU rows within a tile in a picture. A tile can be partitioned into multiple bricks, each of which consists of one or more CTU rows within the tile. A tile that is not partitioned into multiple bricks can also be referred to as a brick. Tile scanning is a specific sequential ordering of the CTUs of a partitioned picture, where the CTUs are sequentially ordered in the CTU raster scan of a tile, the tiles within a tile are sequentially ordered in the tile raster scan of the tile, and the tiles within a picture are sequentially ordered in the tile raster scan of the picture. A tile is a rectangular region of CTUs within a specific tile column and a specific tile row in a picture. A tile column is a rectangular region of CTUs 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 tile row is a rectangular region of CTUs whose height is specified by a syntax element in the picture parameter set and whose width is equal to the width of the picture. Tile scanning is a specific sequential ordering of the CTUs of a partitioned picture, where the CTUs are sequentially ordered in the CTU raster scan of a tile, and the tiles within a picture are sequentially ordered in the tile raster scan of the 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 be composed of multiple complete tiles, or only of a consecutive sequence of complete tiles of a single tile. In this document, tile groups and slices can be used interchangeably. For example, in this document, a tile group / tile group header can be referred to as a slice / slice header.

[0044] A pixel or pel can mean the smallest unit that makes up a picture (or image). Additionally, "sample" can be used as a term corresponding to a pixel. A sample can generally represent a pixel or a pixel value, and can represent only the pixel / pixel value of the luminance component or only the pixel / pixel value of the chrominance component.

[0045] A unit can represent the basic unit of image processing. A unit can include at least one of a specific area of a picture and information related to that area. A unit can include one luminance block and two chrominance (e.g., cb, cr) blocks. In some cases, a unit can be used interchangeably with terms such as block or region. Generally, an M×N block can include an array of samples (or sample array) of M columns and N rows or a set (or array) of transform coefficients. Alternatively, a sample can mean a pixel value in the spatial domain, and when such a pixel value is transformed to the frequency domain, it can mean a transform coefficient in the frequency domain.

[0046] In some cases, a unit can be used interchangeably with terms such as block or region. Generally, an M×N block can represent a set of samples or transform coefficients consisting of M columns and N rows. A sample can generally represent a pixel or a pixel value, can represent only the pixel / pixel value of the luminance component or only the pixel / pixel value of the chrominance component. A sample can be used as a term corresponding to a pixel or pel of a picture (or image).

[0047] Figure 2 FIG. is a diagram schematically illustrating the configuration of a video / image coding device to which embodiments of the present disclosure can be applied. Hereinafter, a device referred to as a video coding device can include an image coding device.

[0048] Refer to Figure 2 , the coding device 200 includes an image partitioner 210, a predictor 220, a residual processor 230, an entropy encoder 240, an adder 250, a filter 260, and a memory 270. The predictor 220 can include an inter-frame predictor 221 and an intra-frame predictor 222. The residual processor 230 can include a transformer 232, a quantizer 233, a dequantizer 234, and an inverse transformer 235. The residual processor 230 can also include a subtractor 231. The adder 250 can 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 can be configured by at least one hardware component (e.g., an encoder chipset or a processor). Additionally, the memory 270 can include a decoded picture buffer (DPB), or can be configured by a digital storage medium. The hardware component can also include the memory 270 as an internal / external component.

[0049] 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 largest coding unit (LCU) according to a quadtree binary tree ternary tree (QTBTTT) structure. For example, a coding unit may be partitioned into multiple 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, the quadtree structure may be applied first, and then the binary tree structure and / or the ternary structure may be applied later. Alternatively, the binary tree structure may be applied first. The coding process according to the present disclosure may be performed based on the final coding unit that is no longer partitioned. In this case, depending on the image characteristics and coding efficiency, etc., the largest coding unit may be used as the final coding unit, or if necessary, the coding unit may be recursively partitioned into coding units with a deeper depth and the coding unit with an optimal size may be used as the final coding unit. Here, the coding process may include processes of prediction, transformation, and reconstruction (to be described later). As another example, the processing unit may further include a prediction unit (PU) or a transformation unit (TU). In this case, each of the prediction unit and the transformation unit may be partitioned or divided from the above-mentioned final coding unit. The prediction unit may be a unit for sample prediction, and the transformation unit may be a unit for deriving transformation coefficients and / or a unit for deriving a residual signal from the transformation coefficients.

[0050] The encoding device 200 may subtract a prediction signal (prediction block, prediction sample array) output from the inter-frame predictor 221 or the intra-frame predictor 222 from an 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 the subtractor 231. The predictor may perform prediction on a processing target block (hereinafter, referred to as the current block) and generate a prediction block including the prediction samples of the current block. The predictor may determine whether to apply intra-frame prediction or inter-frame prediction in units of the current block or CU. As will be described later in the description of each prediction mode, the predictor may generate various types of information about the prediction (for example, prediction mode information) 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.

[0051] The intra predictor 222 may predict the current block by referring to samples in the current picture. Depending on the prediction mode, the samples referred to may be located near the current block or may be separated. In intra prediction, the prediction mode may include a plurality of non - directional modes and a plurality of directional modes. For example, the non - directional modes may include the DC mode and the planar mode. For example, depending on the level of detail of the prediction direction, the directional modes 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 according to the settings. The intra predictor 222 may use the prediction mode applied to neighboring blocks to determine the prediction mode applied to the current block.

[0052] The inter predictor 221 may derive the predicted block of the current block based on the reference block (reference sample array) specified by the motion vector on the reference picture. Here, in order to reduce the amount of motion information transmitted in the inter - 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 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 - prediction direction (L0 prediction, L1 prediction, Bi - prediction, etc.) information. In the case of inter - prediction, 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 predictor 221 may configure a motion information candidate list based on neighboring blocks and generate information indicating which candidate is used to derive the motion vector and / or reference picture index of the current block. Inter - prediction may be performed based on various prediction modes. For example, in the skip mode and the merge mode, the inter predictor 221 may use the motion information of neighboring blocks as the motion information of the current block. In the skip mode, different from the merge mode, the residual signal may not be sent. The motion vector prediction (MVP) mode may indicate the motion vector of the current block by using the motion vector of a neighboring block as a motion vector predictor and signaling the motion vector difference.

[0053] 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 simultaneously. This may be referred to as combined inter and intra prediction (CIIP). In addition, the predictor may be based on the intra block copy (IBC) prediction mode or the palette mode for predicting a block. The IBC prediction mode or the palette mode may be used for image / video compilation of content such as games, e.g., screen content compilation (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 regarded as an example of intra compilation or intra prediction. When the palette mode is applied, the sample values in the picture may be signaled based on the information on the palette table and the palette index.

[0054] The prediction signal generated by the predictor (including the inter predictor 221 and / or the intra predictor 222) may be used to generate a reconstructed signal or may be used to generate a residual signal.

[0055] 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 the following: discrete cosine transform (DCT), discrete sine transform (DST), graph-based transform (GBT), or conditional nonlinear transform (CNT). Here, GBT means a transform obtained from a graph when the relationship information between pixels is illustrated as 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 a square pixel block having the same size, or may also be applied to a variable-size block that is not square.

[0056] The quantizer 233 quantizes the transform coefficients and sends the quantized transform coefficients to the entropy encoder 240, and the entropy encoder 240 encodes the quantized signal (information on the quantized transform coefficients) and outputs the encoded signal as a bitstream. The information on 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 the coefficient scan order, and also generate information on the quantized transform coefficients based on the quantized transform coefficients in the one-dimensional vector form.

[0057] 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, together or individually, information necessary for video / image reconstruction other than the quantized transform coefficients (e.g., values of syntax elements, etc.). The encoded information (e.g., encoded video / image information) may be sent or stored in the form of a bitstream in units of Network Abstraction Layer (NAL). The video / image information may also include information on various parameter sets, such as Adaptive Parameter Set (APS), Picture Parameter Set (PPS), Sequence Parameter Set (SPS), or Video Parameter Set (VPS). Additionally, the video / image information may also include general constraint information. In this document, information signaled / sent from an encoding device to a decoding device and / or syntax elements may be included in the video / image information. The video / image information may be encoded through the aforementioned encoding process and thus included in the bitstream. The bitstream may be sent through 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 transmission unit (not shown) for transmitting the signal output from the entropy encoder 240 and / or a storage unit (not shown) for storing the signal may be configured as internal / external elements of the encoding device 200, or the transmission unit may also be included in the entropy encoder 240.

[0058] The quantized transform coefficients output from the quantizer 233 may be used to generate a prediction signal. For example, an inverse quantization and inverse transform may be applied to the quantized transform coefficients by the dequantizer 234 and the inverse transform unit 235 to reconstruct a residual signal (residual block or residual samples). The adder 250 may 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). For example, when applying the skip mode, when there is no residual for the target block to be processed, the predicted block may be used as the reconstructed block. The adder 250 may be referred to as a restorer or a restored block generator. The generated reconstructed signal may be used for intra-frame prediction of the next target block within the current picture, and may also be used for inter-frame prediction of the next picture after filtering, as described below.

[0059] Meanwhile, Luminance Mapping and Chrominance Scaling (LMCS) may also be applied during picture encoding and / or reconstruction processing.

[0060] 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, the various filtering methods can 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 will be 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 bitstream.

[0061] The modified reconstructed picture sent to the memory 270 can be used as a reference picture in the inter-frame predictor 221. When inter-frame prediction is applied by the encoding device, prediction mismatch between the encoding device 200 and the decoding device can be avoided and the encoding efficiency can be improved.

[0062] The DPB of the memory 270 can store the corrected reconstructed picture to be used as a reference picture in the inter-frame predictor 221. The memory 270 can store the motion information of the blocks from which the motion information in the current picture is derived (or encoded) and / or the motion information of the blocks in the already reconstructed pictures. The stored motion information can be transmitted to the inter-frame predictor 221 to be used as the motion information of spatially adjacent blocks or temporally adjacent blocks. The memory 270 can store the reconstructed samples of the reconstructed blocks in the current picture and can transmit the reconstructed samples to the intra-frame predictor 222.

[0063] Figure 3 is a diagram for schematically explaining the configuration of a video / image decoding device to which embodiments of the present disclosure can be applied.

[0064] Referring to Figure 3 , the decoding device 300 can 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 can include an inter-frame predictor 331 and an intra-frame predictor 332. The residual processor 320 can 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 can be configured by hardware components (e.g., a decoder chipset or a processor). Additionally, the memory 360 can include a decoded picture buffer (DPB) or can be configured by a digital storage medium. The hardware components can also include the memory 360 as an internal / external component.

[0065] When a bitstream including video / image information is input, the decoding device 300 can 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 units for decoding may be compilation units, and the compilation units may be divided from the compilation tree units or the largest compilation units 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 units. In addition, the reconstructed image signal decoded and output by the decoding device 300 may be reproduced by a reproduction device.

[0066] 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 the adaptive parameter set (APS), the picture parameter set (PPS), the sequence parameter set (SPS), or the video parameter set (VPS). In addition, the video / image information may also include general constraint information. The decoding device may also decode a picture 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 in 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 the 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.

[0067] The residual processor 320 may derive a residual signal (residual block, residual sample, residual sample array). Additionally, information regarding 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 component 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 the 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-prediction unit 332, and an intra-prediction unit 331.

[0068] 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 scan order executed in the encoding device. The dequantizer 321 may perform dequantization on the quantized transform coefficients using a quantization parameter (e.g., quantization step information) and obtain the transform coefficients.

[0069] The inverse transformer 322 inverse-transforms the transform coefficients to obtain a residual signal (residual block, residual sample array).

[0070] In this document, at least one of quantization / dequantization and / or transformation / inverse transformation may be omitted. When quantization / dequantization is omitted, the quantized transform coefficients may be referred to as transform coefficients. When transformation / inverse transformation is omitted, the transform coefficients may be referred to as coefficients or residual coefficients, or for the sake of consistency in expression, may still be referred to as transform coefficients.

[0071] In this document, the quantized transform coefficients and the transform coefficients may be referred to as transform coefficients and scaled transform coefficients, respectively. In this case, the residual information may include information regarding the transform coefficients, and the information regarding the transform coefficients may be signaled via a residual coding syntax. The transform coefficients may be derived based on the residual information (or the information regarding the transform coefficients), and the scaled transform coefficients may be derived by inverse-transforming (scaling) the transform coefficients. The residual samples may be derived based on the inverse-transform (transformation) of the scaled transform coefficients. This may also be applied / expressed in other parts of this document.

[0072] The predictor 330 can perform prediction on the current block and generate a predicted block including the predicted samples of the current block. The predictor can determine whether to apply intra prediction or inter prediction to the current block and determine a specific intra / inter prediction mode based on the information about the prediction output from the entropy decoder 310.

[0073] The predictor 330 can generate a prediction signal based on various prediction methods described below. For example, the predictor can apply intra prediction or inter prediction for predicting a block, and can also apply intra prediction and inter prediction simultaneously. This can be referred to as combined inter and intra prediction (CIIP). Additionally, the predictor can predict a block based on the intra block copy (IBC) prediction mode or the palette mode. The IBC prediction mode or the palette mode can be used for image / video compilation of content such as games, for example, screen content compilation (SCC). IBC can basically perform prediction within the current picture, but can be performed similarly to inter prediction such that a reference block is derived within the current picture. That is, IBC can use at least one of the inter prediction techniques described in this document. The palette mode can be regarded as an example of intra compilation or intra prediction. When the palette mode is applied, information about the palette table and the palette index can be included in and signaled in the video / image information.

[0074] The intra predictor 331 can predict the current block by referring to the samples in the current picture. Depending on the prediction mode, the samples referred to can be located near the current block or can be separated from the current block. In intra prediction, the prediction mode can include a plurality of non - directional modes and a plurality of directional modes. The intra predictor 331 can determine the prediction mode applied to the current block by using the prediction mode applied to the adjacent blocks.

[0075] The inter predictor 332 can derive the predicted block of the current block based on the reference block (reference sample array) specified by the motion vector on the reference picture. In this case, in order to reduce the amount of motion information transmitted in the inter prediction mode, the motion information can be predicted in units of blocks, sub - blocks, or samples based on the correlation of the motion information between the adjacent blocks and the current block. The motion information can include a motion vector and a reference picture index. The motion information can also include information about the inter prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.). In the case of inter prediction, the adjacent blocks can include spatially adjacent blocks present in the current picture and temporally adjacent blocks present in the reference picture. For example, the inter predictor 332 can construct a motion information candidate list based on the adjacent blocks and derive the motion vector and / or the reference picture index of the current block based on the received candidate selection information. Inter prediction can be performed based on various prediction modes, and the information about the prediction can include information indicating the inter prediction mode used for the current block.

[0076] 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 a predictor (including the inter-frame predictor 332 and / or the intra-frame predictor 331). If there is no residual for the target block to be processed, for example, in the case of applying the skip mode, the prediction block can be used as the reconstructed block.

[0077] The adder 340 can be referred to as a reconstructor or a reconstructed block generator. The generated reconstructed signal can be used for intra-frame prediction of the next block to be processed in the current picture, and as will be described subsequently, can also be output through filtering or can also be used for inter-frame prediction of the next picture.

[0078] In addition, a luminance mapping with chroma scaling (LMCS) can also be applied to the picture decoding process.

[0079] 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 corrected reconstructed picture by applying various filtering methods to the reconstructed picture and store the corrected reconstructed picture in the memory 360, specifically, in the DPB of the memory 360. The various filtering methods can include, for example, deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, etc.

[0080] 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 within the current picture is derived (decoded) and / or the motion information of the block within the already reconstructed picture. The stored motion information can be transmitted to the inter-frame predictor 260 to be used as the motion information of spatially adjacent blocks or temporally adjacent blocks. The memory 360 can store the reconstructed samples of the reconstructed blocks within the current picture and transmit the reconstructed samples to the intra-frame predictor 331.

[0081] In this document, the embodiments described in the filter 260, the inter-frame predictor 221, and the intra-frame predictor 222 of the encoding device 200 can be equally applied to or correspond to the filter 350, the inter-frame predictor 332, and the intra-frame predictor 331.

[0082] Meanwhile, the video / image compilation method according to this document can be performed based on the following partitioning structure. Specifically, the above processes of prediction, residual processing ((inverse) transformation and (de)quantization), syntax element compilation, and filtering can be performed according to the CTUs and CUs (and / or TUs and PUs) derived based on the partitioning structure. The block partitioning process can be performed by the image partitioner 210 of the above encoding device, and the partitioning-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 partitioning structure of the current picture based on the partitioning-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 region. Meanwhile, the CU size generally can represent the luminance component (sample) compilation block (CB) size. The TU size generally can represent the luminance component (sample) transform block (TB) size. The chrominance 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 of the picture / image (chrominance format, e.g., 4:4:4, 4:2:2, 4:2:0, etc.). 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 transformation / inverse transformation can be performed in units of TUs (TBs). In addition, for example, in the case of applying intra prediction, the intra prediction mode / type can be derived in units of CUs (or CBs), and the neighboring reference sample derivation and predicted sample generation processes can be performed in units of TUs (or TBs). In this case, one or more TUs (or TBs) can exist in one CU (or CB) region, and in this case, multiple TUs (or TBs) can share the same intra prediction mode / type.

[0083] In addition, in the video / image compilation according to this document, the image processing unit may have a hierarchical structure. A picture can be partitioned into one or more tiles, blocks, slices, and / or tile groups. A slice can include one or more blocks. A block can include one or more CTU rows within a tile. A slice can include an integer number of blocks of a picture. A tile group can include one or more tiles. A tile can include one or more CTUs. A CTU can be partitioned into one or more CUs. A tile represents a rectangular region of CTUs within a specific tile column and a specific tile row in a picture. According to the raster scan of tiles in a picture, a tile group can include an integer number of tiles. A slice header can carry information / parameters that can be applied to the corresponding slice (blocks in the slice). In the case where the encoding / decoding device has a multi-core processor, the encoding / decoding processes of tiles, slices, blocks, and / or tile groups can be processed in parallel. In this document, a slice or a tile group can be used interchangeably. That is, a tile group header can be referred to as a slice header. Here, a slice can have one of the slice types, including an intra (I) slice, a predictive (P) slice, and a bi-predictive (B) slice. When predicting blocks in an I slice, inter-frame prediction can be not used, and only intra-frame prediction can be used. Of course, even in this case, signaling can be performed by compiling the original sample values without prediction. Regarding blocks in a P slice, intra-frame prediction or inter-frame prediction can be used, and in the case of using inter-frame prediction, only one-way prediction can be used. Meanwhile, regarding blocks in a B slice, intra-frame prediction or inter-frame prediction can be used, and in the case of using inter-frame prediction, bi-prediction can be used to the maximum extent possible.

[0084] The encoding device can determine the tile / tile group, block, slice, and the maximum and minimum compilation unit sizes in consideration of compilation efficiency or parallel processing, or according to the characteristics of the video image (e.g., resolution), and information about them or information that can induce them can be included in the bitstream.

[0085] The decoding device can obtain information indicating the tile / tile group, block, and slice of the current picture and whether the CTUs in the tile have been partitioned into multiple compilation units. By obtaining (sending) such information only under specific conditions, efficiency can be enhanced.

[0086] Meanwhile, as described above, an image may include multiple slices, and a slice may include a slice header and slice data. In this case, an image header may be further added for the multiple slices (a set of slice headers and slice data) in an image. The image header (image header syntax) may include information / parameters that can be commonly applied to the image. The slice header (slice header syntax) may include information / parameters that can be commonly applied to the slice. The Adaptive Parameter Set (APS) or Picture Parameter Set (PPS) may include information / parameters that can be commonly applied to one or more images. The Sequence Parameter Set (SPS) may include information / parameters that can be commonly applied to one or more sequences. The Video Parameter Set (VPS) may include information / parameters that can be commonly applied to multiple layers. The Decoding Parameter Set (DPS) may include information / parameters that can be commonly applied to the entire video. The DPS may include information / parameters related to the concatenation of the Compiled Video Sequence (CVS).

[0087] In this document, the high-level syntax may include at least one of the APS syntax, PPS syntax, SPS syntax, VPS syntax, DPS syntax, image header syntax, and slice header syntax.

[0088] In addition, for example, information such as the partitioning and configuration of tiles / tile groups / tuples / slices can be configured in an encoding device based on the high-level syntax and then can be delivered (or transmitted) to a decoding device in bitstream format.

[0089] An image may be partitioned into one or more tile rows and one or more tile columns. A tile is a sequence of CTUs that cover a rectangular area of the image. A tile may be partitioned into one or more tuples, and each tuple may be configured by multiple CTU rows. A tile that is not partitioned into multiple tuples may also be referred to as a tuple. However, a tuple that is a subset of a tile is not called a tile. A slice may include multiple tiles or multiple tuples of a tile.

[0090] Figure 4 An example of the image decoding process is shown.

[0091] In image / video compilation, images that configure the image / video may be encoded / decoded according to the decoding order. The picture order corresponding to the output order of the decoded pictures may be configured differently from the decoding order. And when performing inter prediction based on the configured picture order, forward prediction and backward prediction may be performed.

[0092] Figure 4 A general example of the picture decoding process to which the embodiments of the present disclosure can be applied is shown. In Figure 4 , S400 may be as described above in Figure 3The entropy decoder 310 of the decoding device described in [description] performs S410, the predictor 330 can perform S410, the residual processor 320 can perform S420, the adder 340 can perform S430, and the filter 350 can perform S440. S400 can include the information decoding process described in this specification, S410 can include the inter-frame / intra-frame prediction process described in this specification, S420 can include the residual processing process described in this specification, S430 can include the block / picture reconstruction process described in this specification, and S440 can include the loop filtering process described in this specification.

[0093] Reference Figure 4 , as described above Figure 3 In the description above, the picture decoding process generally may include (by decoding) a process of obtaining image / video information from a bitstream (S400), a picture reconstruction process (S410 to S430), and a loop filtering process (S440) for reconstructing a picture. The picture reconstruction process may be performed based on predicted samples and residual samples obtained by performing an inter-frame / intra-frame prediction process (S410) and a residual processing process (S420, the dequantization and inverse transformation process of 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 as to be used as a reference image during the inter-frame prediction process when decoding a picture 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 as to be used as a reference picture during the inter-frame prediction process when decoding a picture 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 part or all of the loop filtering process may be skipped. Additionally, 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 process, the sample adaptive offset (SAO) process, the adaptive loop filter (ALF) process, and the bilateral filter process may be applied sequentially. For example, after applying the deblocking filtering process to the reconstructed picture, the SAO process may be performed. Alternatively, for example, after applying the deblocking filtering process to the reconstructed picture, the ALF process may be performed. This may also be similarly performed in the encoding device.

[0094] Figure 5An example of a picture encoding process is shown.

[0095] Figure 5 A general example of a picture encoding process to which embodiments of the present disclosure can be applied is shown. In Figure 5 S500 can be executed by the predictor 220 of the encoding device described above in Figure 2 S510 can be executed by the residual processor 230, and S520 can be executed by the entropy encoder 240. S500 can include the inter / intra prediction processes described in this specification, S610 can include the residual processing processes described in this specification, and S520 can include the information encoding processes described in this specification.

[0096] Referring to Figure 5 as described above in Figure 2 the image encoding process generally can include a process of encoding information for picture reconstruction (e.g., prediction information, residual information, partition information, etc.) and outputting the encoded information in bitstream format, a process of generating a reconstructed picture for the current picture, and an optional process of applying loop filtering to the reconstructed picture. The encoding device can derive residual samples (modified) from the quantized transform coefficients through the dequantizer 234 and the inverse transformer 235, and then the encoding device can generate a reconstructed picture based on the prediction samples and the (modified) residual samples that are the output of S500. The reconstructed picture generated as described above can be the same as the above-mentioned reconstructed picture generated in the decoding device. A modified reconstructed picture can be generated by performing a loop filtering process on the reconstructed picture, and then stored in the decoded picture buffer or the memory 270 of the decoding device. Also, as in the decoding device, when encoding a picture, during the inter prediction process, the modified reconstructed picture can be used as a reference picture. As described above, in some cases, part or all of the loop filtering process can be skipped. When the loop filtering process is executed, the (loop) filtering related information (parameters) can be encoded in the entropy encoder 240 and then sent in bitstream format, and the decoding device can perform the loop filtering process by using the same method as the encoding device based on the filtering related information.

[0097] By performing the above loop filtering process, noises such as blocking artifacts and ringing artifacts that occur during the compilation of images / motion picture images can be reduced, and the subjective / objective visual quality can be enhanced. Additionally, by having both the encoding device and the decoding device perform the loop filtering process, the encoding device and the decoding device can derive the same prediction results, increase the reliability of image compilation, and reduce the size (or amount) of data to be sent for image compilation.

[0098] As described above, a picture reconstruction process may be performed in a decoding device as well as an encoding device. A reconstructed block may be generated for each block unit based on intra prediction / inter prediction, and a reconstructed picture including the reconstructed blocks may 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 may be reconstructed based only on intra prediction. Meanwhile, 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 may be reconstructed based on intra prediction or inter prediction. In this case, inter prediction may be applied to some blocks within the current picture / slice / tile group, and intra prediction may be applied to the remaining blocks. The color components of a picture may include a luminance component and a chrominance component. And, unless explicitly defined (or restricted) in this specification, the methods and embodiments proposed in this specification may be applied to the luminance component and the chrominance component.

[0099] Meanwhile, as described above, high-level syntax (HLS) may be compiled / signaled for video / image encoding. The encoded picture may be configured by one or more slices. The parameters describing the encoded picture are signaled within the picture header, and the parameters describing the slice are signaled within the slice header. The picture header is carried in its own NAL unit format. And, the slice header exists at the start (or beginning) of the NAL unit including the payload of the slice (i.e., the slice data).

[0100] Each picture is associated with a picture header. The picture may be configured by different types of slices (intra-encoded slices (i.e., I slices) and inter-encoded slices (i.e., P slices and B slices)). Thus, the picture header may include the syntax elements required for the intra slices and the inter slices of the picture.

[0101] A picture may be partitioned (or divided) into sub-pictures, tiles, and / or slices. The sub-picture signaling may exist in the sequence parameter set (SPS). And, the tile and square slice signaling may exist in the picture parameter set (PPS). The raster scan slice signaling may exist in the slice header.

[0102] For example, regarding the partitioning of a picture, the syntax elements shown in Table 1 below may be included in the SPS syntax.

[0103] [Table 1]

[0104]

[0105] The syntax elements shown in Table 2 below may be included in the PPS syntax.

[0106] [Table 2]

[0107]

[0108]

[0109] 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 including 0 to RowHeight[tileY] - 1. 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 in the PPS, the value of num_slices_in_tile_minus1[i] is derived as 0.

[0110] slice_height_in_ctu_minus1[i] + 1 indicates the height of the i-th rectangular slice in terms 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 including 0 to RowHeight[tileY] - 1. Here, tileY is the index of the tile row that includes the i-th slice.

[0111] The syntax elements shown in Table 3 below can be included in the slice header syntax.

[0112] [Table 3]

[0113]

[0114] Referring to Tables 1 to 3, in the current tile and slice design, a rectangular slice can include one or more tiles. Alternatively, a rectangular slice can include an integer number (or whole number) of CTU rows within a single tile.

[0115] When a rectangular slice includes an integer (or whole number) of CTU rows within a single tile (which corresponds to the case where a tile is partitioned into two or more slices), in the current signaling, the height of each slice is explicitly signaled. However, this type of signaling is not the optimal signaling method.

[0116] The layout of slices within a tile may include cases where the height of slices within the tile, except for the last slice, is uniform, and cases where the height of slices within the tile is non-uniform. When the height of slices within the tile, except for the last slice, is uniform, since the height of all slices within the tile excluding the last slice is the same, it is possible to signal the height of one slice only without explicitly signaling the height of each slice. When the height of slices within the tile is non-uniform, it is necessary to signal the height of each slice within the tile.

[0117] The following drawings are illustrated to describe detailed examples of this specification. The detailed terms of the devices (or apparatuses) specified in the drawings or the detailed terms of signals / information are merely exemplary. Therefore, the technical features of this specification will not be limited only to the detailed terms used in the following drawings.

[0118] This specification provides the following methods to facilitate solving the above problems. The items of each method can be applied individually or can be applied in combination.

[0119] For example, when a tile includes two or more slices, the heights of multiple slices explicitly signaled within the CTU row can be signaled. This can be referred to as the syntax element num_exp_slice_in_tile. In this case, the syntax elements (array of slice_row_height_minus1) of indices 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 for signaling such syntax elements can vary according to the number of CTU rows within the tile. Here, ue(v) represents the syntax element of 0th order Exponential Golomb coding, and u(v) indicates using v bits, where the value of v varies according to the values of other syntax elements.

[0120] The height of each slice from the first slice to the nth slice within the tile is respectively given the value of slice_row_height_minus1 + 1 from 0 to num_exp_slice_in_tile - 1. Here, n is equal to the number of slices within the tile explicitly signaled (num_exp_slice_in_tile).

[0121] New slices are defined within a tile although there are always more than num_exp_slice_in_tile_minus1 + 1 and the remaining CTU rows within the tile are (explicitly) signaled last. In other words, there are slices within a 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.

[0122] 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 according to the CTU rows. 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 that does not include the last slice may be explicitly signaled.

[0123] In this specification, information about slices and / or tiles may include the information and / or syntax elements disclosed in Tables 1 to 3. Image / video information may include the 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 tiles. Information related to slices may include information indicating one or more slices within the current picture, and information related to tiles may include information indicating one or more tiles within the current picture. Tiles including one or more slices and slices including one or more tiles may exist in a picture.

[0124] As an example, in order to represent the partition structure of a picture, the syntax shown in Table 4 and the semantics shown in Table 5 may be used for PPS.

[0125] [Table 4]

[0126]

[0127] [Table 5]

[0128]

[0129] Referring to Table 4 and Table 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 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 including 0 to RowHeight[tileY] - 1. Here, tileY is the index of the tile row including the slice.

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

[0132] The quantity information and the height information can be syntax elements encoded in exponential Golomb.

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

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

[0135] When parsing the quantity information from the PPS, as shown in Table 4, the decoding device can 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 can parse the height information of n slices (starting from slice 0 within the tile to slice (n - 1)) from the PPS. The height information can indicate each of the heights of slice 0 to slice (n - 1) in the Compilation Tree Unit (CTU) rows.

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

[0137] When the remaining height of the tile is equal to or greater than the height of the unified slice, the height of slice n can be derived as the height of the unified slice. And when the remaining height of the tile is less than the height of the unified slice, the height of slice n can be derived as the remaining height. Additionally, when the remaining height of the tile is equal to or greater than the height of the unified slice, an updated remaining height can be derived by subtracting the height of slice n 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 slice (n + 1) 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 slice (n + 1) as the updated remaining height. That is, excluding the last slice within the tile, the heights of the slices starting from slice n 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 (from slice (n - 1) to the slice immediately before the last slice).

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

[0139] The decoding device can derive the number of slices within a tile 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 tile and information about the number of slices within the tile can be indicated as shown in Table 5 below.

[0140] [Table 6]

[0141]

[0142] In the case of rectangular slices, the list NumCtuInSlice[i] for i in the range from 0 to num_slices_in_pic_minus1 can 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 indicates the picture raster scan addressing of the j-th CTB within the i-th slice, and can be derived as shown in Table 7 below.

[0143] [Table 7]

[0144]

[0145] As another embodiment, to represent the partitioning structure of a picture, the syntax shown in Table 8 and the semantics shown in Table 9 can be used for PPS.

[0146] [Table 8]

[0147]

[0148] [Table 9]

[0149]

[0150] Referring to Table 8 and Table 9, if the value of uniform_slice_spacing_flag[i] is equal to 1, this indicates that the CTU rows are evenly distributed (or scattered) across the entire tile and are 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 rows may or may not be evenly distributed (or scattered) across the entire tile and are signaled by using the syntax elements num_slices_in_tile_minus1[i] and slice_height_in_ctu_minus1[i].

[0151] 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 of the last slice of the excluded patch in units of CTB. The value of slice_height_in_ctu_minus1[i] should be in the range including 0 to RowHeight[tileY] - 1. Here, tileY is the index of the patch row including the slice.

[0152] 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 patch 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 including 0 to RowHeight[tileY] - 1. Here, tileY is the index of the patch row including 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.

[0153] 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 patch. The value of slice_height_in_ctu_minus1[i] should be in the range including 0 to RowHeight[tileY] - 1. Here, tileY is the index of the patch row including the i-th slice.

[0154] For example, the encoding device can 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 slices of the current picture.

[0155] 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.

[0156] For example, variables NumSlicesInTileMinus1[i] and SliceHeightInCtuMinus1[i + k] related to the number information and height information of slices within a tile may be derived as follows. Here, k may range from 0 to NumSlicesInTileMinus1[i].

[0157] [Table 10]

[0158]

[0159] 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 indicates 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.

[0160] [Table 11]

[0161]

[0162] Figure 6 and Figure 7Generally examples of a video / image encoding method and related components according to embodiments of the present disclosure are shown respectively.

[0163] Figure 6 The video / image encoding method disclosed in can be performed by Figure 2 and Figure 7 the (video / image) encoding device 200 disclosed in. More specifically, for example, Figure 6 S600 of can be performed by the picture partitioner 210 of the encoding device 200, and S610 and S620 can be performed by the entropy encoder 240 of the encoding device 200. Figure 6 The video / image encoding method disclosed can include the embodiments described above in this specification.

[0164] More specifically, referring to Figure 6 and Figure 7 , the picture partitioner 210 of the encoding device can derive slices within a tile of the current picture (S600). For example, the picture partitioner 210 can partition an input image (or picture, frame) into one or more CUs. The input image can include one or more pictures. A picture can be partitioned into one or more tiles, patches, slices, and / or tile groups. A slice can include one or more patches, tiles, and / or tile groups. A tile can include one or more CTU rows. A tile group can include one or more tiles. A tile can include one or more CTUs. A CTU can be partitioned into one or more CUs. When a specific slice within the current picture is a rectangular slice, the picture partitioner 210 can partition the rectangular slice into multiple tiles, and among the multiple tiles, the picture partitioner 210 can partition at least one tile, and then derive multiple rectangular slices.

[0165] The predictor 220 of the encoding device can perform prediction on the current block, and then can generate a prediction sample (predicted block) of the current block. The predictor 220 can determine, in units of the current block or CU, whether intra prediction is being applied, or whether inter prediction is being applied. The predictor 220 can generate various information related to prediction (prediction-related information), and deliver the generated prediction-related information to the entropy encoder 240. Here, the prediction-related information can 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, a prediction sample can 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 can be generated in the intra predictor 222 of the predictor 220.

[0166] The residual processor 230 of the encoding device may generate residual samples and residual information based on the predicted 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.

[0167] The adder (or reconstructor) of the encoding device may generate reconstructed samples (reconstructed picture, reconstructed block, reconstructed sample array) by adding the residual samples generated in the residual processor 230 and the predicted samples generated in the inter-frame predictor 221 or the intra-frame predictor 222.

[0168] The entropy encoder 240 of the encoding device may generate partition-related information based on the partition structure derived in the image partitioner 210. The partition-related information may include information (quantity information) about the number of slices whose height of each slice within the tile is explicitly signaled, and information (height information) about the height of each slice whose height of each slice is explicitly signaled. For example, the entropy encoder 240 may generate quantity information related to the number of slices whose height of each slice within the tile is explicitly signaled (provided) based on the slices derived in the image partitioner 210, and height information related to the height of each slice whose height of each slice is explicitly signaled (provided) (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.

[0169] The entropy encoder 240 may encode the image information, which includes partition-related information including quantity information and height information, prediction-related information generated in the predictor 220, and / or residual information generated in the residual processor 230 (S620). The information encoded in the entropy encoder 240 may be output in the form of a bitstream. The bitstream may be sent to the decoding device via a network or a storage medium.

[0170] For example, the entropy encoder 240 may include image information that includes, based on Tables 4 and 5 above, the syntax element num_exp_slices_in_tile as quantity information and the syntax element exp_slice_height_in_ctu_minus1 as height information. The height information may indicate, in units of CTU rows, the height of each slice within the tile for which its slice height is explicitly signaled, and to this end, the height information may include syntax elements for each slice for which its slice height is explicitly signaled. The number of syntax elements included in the image information may be the same as the quantity information value.

[0171] As another example, the entropy encoder 240 may encode 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 above. 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.

[0172] The entropy encoder 240 may signal the quantity information and the height information via a picture parameter set (PPS) within the image information. In this case, the entropy encoder 240 may include the quantity information and / or the height information by using the exponential Golomb method.

[0173] Figure 8 and Figure 9 respectively illustrate general examples of a video / image decoding method and related components according to embodiments of the present disclosure.

[0174] Figure 8 The video / image decoding method disclosed in Figure 3 and Figure 9 may be performed by the (video / image) decoding device 300 disclosed in Figure 8 Specifically, for example, Figure 8 S800 to S830 of Figure 8 may be performed by the entropy decoder 310 of the decoding device 300, and

[0175] Reference Figure 8 and Figure 9 The entropy decoder 310 of the decoding device can 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 (quantity information) about the number of slices in which each slice height is explicitly signaled in the slices within the tile of the current picture, information (height information) about the height of each slice in which each slice height is explicitly signaled, etc.

[0176] For example, the entropy decoder 310 can parse information (quantity information) related to the number of slices in which each slice height is explicitly signaled in the slices within the tile of the current picture from the bitstream (S800), and can parse information (height information) related to the height of each slice in which each slice height is explicitly signaled from the bitstream based on the quantity information (S810). More specifically, the entropy decoder 310 can parse the quantity information and the height information from the picture parameter set (PPS) of the bitstream based on Table 4 above. Here, the quantity information can be parsed based on information about the width and height of the slice including the tile. At this time, the slice including the tile and / or the slice within the tile can be a rectangular slice. The quantity information and the height information can be syntax elements compiled by exponential Golomb. The height information may include syntax elements for each slice in which each slice height is explicitly signaled. The number of syntax elements may be the same as the quantity information value.

[0177] For example, the entropy decoder 310 can 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 can 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 can 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).

[0178] 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 tile based on the height information (S820). And, the entropy decoder 310 may derive the height of the nth slice within the tile 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 tile. 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 tile are the same as the height of the (n - 1)th slice. Thus, the heights of the slices from the nth slice to the last slice within the tile may be uniform except for the last slice within the tile. The entropy decoder 310 may derive the height of the last slice within the tile based on the remaining height after subtracting the heights of the other slices within the tile from the height of the tile (S840). When deriving the heights of all the slices within the tile, the entropy decoder 310 may derive the number of slices within the tile (S850). Here, the number of slices within the tile may correspond to the number of slices from the 0th slice to the last slice within the tile.

[0179] The decoding device 300 may decode the current picture based on the slices 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 prediction and / or intra prediction based on the prediction-related information obtained from the entropy decoder 310 such that prediction samples are generated. 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.

[0180] Thereafter, loop filtering processes such as deblocking filtering, SAO, and / or ALF processes may be applied to the reconstructed picture as needed to enhance the subjective / objective picture quality.

[0181] 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.

[0182] When the syntax element slice_rows_height_in_ctu_minus1 is parsed, the entropy decoder 310 may derive the height of the remaining slices excluding the last slice within the tile as the value of slice_rows_height_in_ctu_minus1.

[0183] 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 respectively as the height of each slice within the tile.

[0184] Although the method has been described in the above embodiments based on a flowchart listing steps or blocks in sequence, the steps of the present disclosure are not limited to a specific order, and a certain step may be performed in different steps or in a different order or simultaneously with respect to the above order. In addition, those of ordinary skill in the art should understand 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.

[0185] 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.).

[0186] When implementing an embodiment of the present disclosure in software, the above-mentioned method may be implemented by modules (processes or functions) that execute the above-mentioned functions. The modules may be stored in a memory and executed by a processor. The memory may be installed inside or outside the processor and may be connected to the processor via various well-known devices. The processor may include an application-specific integrated circuit (ASIC), other chip sets, 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, an embodiment according to the present disclosure may be implemented and executed on a processor, a microprocessor, a controller, or a chip. For example, the functional units illustrated in the corresponding figures may 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 algorithms may be stored in a digital storage medium.

[0187] In addition, a decoding device and an encoding device to which an embodiment of the present disclosure is applied may be included in a multimedia broadcast transceiver, a mobile communication terminal, a home theater video device, a digital cinema 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, an in-vehicle terminal (e.g., an in-vehicle terminal for a vehicle (including an autonomous vehicle), an aircraft terminal, or a ship terminal), and a medical video device; and may be used to process image signals or data. For example, an OTT video device may include a game console, a Blueray player, an Internet-connected TV, a home theater system, a smart phone, a tablet PC, and a digital video recorder (DVR).

[0188] In addition, the processing method according to the embodiments of the present disclosure can be generated in the form of a program executable by a computer and can be stored in a computer-readable recording medium. Multimedia data having a data structure according to the embodiments 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 can include, for example, Blu-ray Disc (BD), Universal Serial Bus (USB), ROM, PROM, EPROM, EEPROM, RAM, CD-ROM, magnetic tape, floppy disk, and 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 bitstream generated by an encoding method can be stored in a computer-readable recording medium or can be transmitted through a wired or wireless communication network.

[0189] In addition, the embodiments of the present disclosure can be implemented as a computer program product based on 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.

[0190] Figure 10 An example of a content streaming system to which the embodiments of this document can be applied is shown.

[0191] Reference Figure 10 , a content streaming system to which the embodiments of this document are applied generally can include an encoding server, a streaming server, a web server, a media storage, a user device, and a multimedia input device.

[0192] The encoding server is used to compress the content input from a multimedia input device such as a smart phone, a camera, a portable video camera, etc. into digital data, generate a bitstream, and transmit it to the streaming server. As another example, in the case where a code stream is directly generated by a multimedia input device such as a smart phone, a camera, a portable video camera, etc., the encoding server can be omitted.

[0193] The bitstream can be generated by an encoding method or a bitstream generation method that can be applied through the embodiments of the present disclosure. And the streaming server can temporarily store the bitstream during the process of sending or receiving the bitstream.

[0194] The streaming server transmits multimedia data to the user device via the web server based on the user's request. The web server serves as a tool to notify the user of what services are available. When the user requests a service they want, 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 such a case, the control server is used to control the commands / responses between the various devices in the content streaming system.

[0195] The streaming server can receive content from a media storage and / or encoding server. For example, in the case of receiving content from the encoding server, the content can be received in real time. In such a case, the streaming server can store the bitstream for a predetermined period of time to smoothly provide the streaming service.

[0196] For example, the user device can include a mobile phone, smartphone, laptop computer, digital broadcast terminal, personal digital assistant (PDA), portable multimedia player (PMP), navigation device, slate PC, tablet PC, ultrabook, wearable device (e.g., watch-type terminal (smartwatch), glasses-type terminal (smart glasses), head-mounted display (HMD)), digital TV, desktop computer, digital signage, etc.

[0197] Each server in the content streaming system can be operated as a distributed server, and in such a case, the data received by each server can be processed in a distributed manner.

Claims

1. A video decoding method performed by a video decoding device, the method comprising: Obtaining picture parameter set information from a bitstream; Parsing, from the picture parameter set information, quantity information related to the number of slices within a tile of a current picture whose height is explicitly signaled; Based on the quantity information, parsing, from the picture parameter set information, height information related to the height of the slices whose height is explicitly signaled; Based on the number of the slices whose height is 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 the height of the last slice within the tile based on the remaining height after subtracting the 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 slices of the current picture, wherein, for the nth slice to the last slice, the parsing of the height information is not performed.

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

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

5. The video decoding method according to claim 4, wherein, 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: Comparing the remaining height of the tile calculated by subtracting the sum of the heights of the slices from the 0th slice to the (n - 1)th slice from the total height of the tile, so as to determine whether the remaining height is equal to or greater than a unified slice height, wherein the unified slice height 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 from the 0th slice to the (n - 1)th slice from the total height of the tile being equal to or greater than the unified slice height, deriving the nth slice having the unified slice height, and wherein, based on the remaining height of the tile calculated by subtracting the sum of the heights of the slices from the 0th slice to the (n - 1)th slice from the total height of the tile being less than the unified slice height, deriving the nth slice having the remaining height.

7. The video decoding method according to claim 6, wherein, Based on the remaining height being equal to or greater than the unified slice height, 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, and the remaining height is calculated by subtracting the sum of the heights of the slices 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 unified slice height, deriving the (n + 1)th slice having the unified slice height, and Wherein, based on the updated remaining height being less than the unified slice height, a (n + 1)-th slice with the updated remaining height is derived.

8. The video decoding method according to claim 1, wherein, The quantity information and the height information include syntax elements compiled by Exponential Golomb.

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

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

11. The video decoding method according to claim 1, wherein, Based on information related to the width and height of the slices including the tile, the quantity information is parsed.

12. A video encoding method performed by a video encoding device, the method comprising: Deriving slices within a tile of a current picture; Generating picture parameter set information including quantity information related to the number of slices within the tile whose height is explicitly signaled and height information related to the height of the slices whose height is explicitly signaled; And Encoding image information including the picture parameter set information, wherein, based on the number of slices whose height is explicitly signaled being equal to n, the height information indicates the height of the 0-th slice to the (n - 1)-th slice within the tile, wherein, based on the height of the (n - 1)-th slice, the height of the n-th slice within the tile is represented, wherein, based on the remaining height after subtracting the heights of other slices within the tile from the height of the tile, the height of the last slice within the tile is derived, and wherein, for the n-th slice to the last slice, encoding of the height information is not performed.

13. A method for transmitting data for a video, the method comprising: Obtaining a bitstream for the video, wherein the bitstream is generated based on: deriving slices within a tile of a current picture; generating picture parameter set information including quantity information related to the number of slices within the tile whose height is explicitly signaled and height information related to the height of the slices whose height is explicitly signaled; and encoding image information including the quantity information and the height information; and Transmitting the data including the bitstream, wherein, based on the number of slices whose height is explicitly signaled being equal to n, the height information indicates the height of the 0-th slice to the (n - 1)-th slice within the tile, wherein, based on the height of the (n - 1)-th slice, the height of the n-th slice within the tile is represented, wherein, based on the remaining height after subtracting the heights of other slices within the tile from the height of the tile, the height of the last slice within the tile is derived, and wherein, for the n-th slice to the last slice, encoding of the height information is not performed.

Images