BR122023024708A2 - VIDEO DECODING APPARATUS, VIDEO CODING APPARATUS AND APPARATUS FOR TRANSMITTING DATA TO A VIDEO - Google Patents

Abstract

This is a method by which a video decoding device decodes a video, in accordance with this document, may comprise the steps of: analyzing, from a bit stream, numerical information related to the number of slices of the which height within a tile of a current figure is explicitly signaled; analyzing, from the bit stream, based on the numerical information, height information relating to the height of the slices of which the height is explicitly signaled; derive the number of slices in the tile based on numerical information and height information; generate prediction samples by predicting the current block of the current figure based on the slices within the tile; generate reconstructed samples based on the prediction samples; and generate a reconstructed figure for the current figure based on the reconstructed samples.

Description

FUNDAMENTALS OF REVELATION Field of Revelation

[001] The present disclosure relates to a method and apparatus for improving the signaling of slice-related information in a system that encodes/decodes an image/video.

Related Technique

[002] Recently, the demand for high-resolution and high-quality image/video, such as 4K, 8K or more Ultra High Definition (UHD) image/video, is increasing in various fields. As the image/video resolution or quality becomes higher, a relatively greater amount of information or bits is transmitted than for conventional image/video data. Therefore, if image/video data is transmitted over a medium such as an existing wired/wireless broadband line or stored on a legacy storage medium, transmission and storage costs increase rapidly.

[003] Additionally, interests and demand are growing for virtual reality (VR) and artificial reality (AR) content and immersive media such as hologram; and the transmission of images/videos exhibiting image/video characteristics different from those of a real image/video, such as game images/videos, are also growing.

[004] Therefore, a highly efficient image/video compression technique is required to effectively compress and transmit, store, or reproduce high-resolution, high-quality images/videos as described above.

SUMMARY OF THE REVELATION Technical Objectives

[005] A technical objective of the present disclosure is to provide a method and apparatus for increasing the coding efficiency of an image/video.

[006] Another technical objective of the present disclosure is to provide a method and apparatus for efficiently signaling information about a slice in a tile.

[007] Yet another technical objective of the present disclosure is to provide a method and apparatus for reducing signaling overhead when delivering (or transferring) information about a slice in a tile.

[008] Yet another technical objective of the present disclosure is to provide a method and apparatus for efficiently delivering (or transferring) information related to a number and height of slices on a tile.

[009] Yet another technical objective of the present disclosure is to provide a method and apparatus for efficiently signaling corresponding slice heights when two or more slices have the same height on a tile.

Technical Solutions

[010] According to an embodiment of the present disclosure, a video decoding method performed by a video decoding apparatus is provided herein. The method may include the steps of analyzing numerical information related to a number of slices each having its height explicitly signaled in a tile of a current figure from a bit stream, analyzing height information related to heights of slices having , each its height explicitly signaled from the bitstream based on numerical information, derive a number of slices in the tile based on numerical information and height information, generate prediction samples by performing prediction on a current block of the current figure based on the slices in the tile, generate reconstructed samples based on the prediction samples, and generate a reconstructed figure for the current figure based on the reconstructed samples, where the height information may include the same number of syntax elements as a value of numeric information, wherein, based on the value of numeric information being equal to n, heights from a 0-th slice to an (n-1)-th slice in the tile can be derived based on the syntax elements, wherein a height of an nth slice in the tile can be derived based on the height of the (n-1)th slice, and wherein a height of a last slice in the tile can be derived based on a height remaining after subtract the heights of other slices in the tile from a tile height.

[011] According to another embodiment of the present disclosure, a video coding method performed by a video coding apparatus is provided herein. The method may include the steps of deriving slices in a tile from a current figure, generating prediction samples by making a prediction in a current tile based on the derived slices, generating residual information based on the prediction samples and an original figure, generating numeric information relating to a number of slices each having their height explicitly signaled on the tile and height information relating to heights of the slices each having their height explicitly based on the derived slices, and encoding image information including the residual information, the numerical information, and the height information, wherein, based on a value of the numerical information being equal to n, the height information may indicate heights from a 0-th slice to an (n-1)-th slice in the tile, wherein a height of an nth slice in the tile can be derived based on the height of the (n-1)th slice, and wherein a height of a last slice in the tile can be derived based on a remaining height after subtracting the heights of other slices in the tile from a tile height.

[012] According to yet another embodiment of the present disclosure, a computer-readable digital recording medium is provided having stored information that induces a video decoding method to be performed by a video decoding apparatus. The video decoding method may include the steps of analyzing numerical information related to a number of slices each having its height explicitly signaled in a tile of a current figure from image information, analyzing height information related to heights of slices each having its height explicitly signaled from the image information based on the numerical information, derive a number of slices in the tile based on the numerical information and the height information, generate prediction samples by performing a prediction in a current tile of the current figure based on the slices in the tile, generate reconstructed samples based on the prediction samples, and generate a reconstructed figure for the current figure based on the reconstructed samples, where the height information may include the same number of syntax elements that a numeric information value, wherein, based on the numeric information value being equal to n, the heights of a 0-th slice to an (n-1)-th slice in the tile can be derived based in syntax elements, wherein a height of an nth slice in the tile can be derived based on the height of the (n-1)th slice, and wherein a height of a last slice in the tile can be derived based on in a height remaining after subtracting the heights of other slices in the tile from a height of the tile.

EFFECTS OF REVELATION

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

[014] According to an embodiment of the present disclosure, information about a slice in a tile can be efficiently signaled.

[015] According to an embodiment of the present disclosure, a signaling overhead can be reduced by delivering (or transferring) information about a slice in a tile.

[016] According to an embodiment of the present disclosure, information related to a number and height of slices in a tile can be efficiently signaled.

[017] According to an embodiment of the present disclosure, when two or more slices have the same height on a tile, the signaling of height information of the slices having the same height can be omitted.

BRIEF DESCRIPTION OF THE DRAWINGS

[018] Figure 1 schematically illustrates an example of a video/image coding system to which the modalities of the present document are applicable.

[019] Figure 2 is a diagram that schematically illustrates a configuration of a video/image coding apparatus to which the modalities of the present document are applicable.

[020] Figure 3 is a diagram that schematically illustrates a configuration of a video/image decoding apparatus to which the modalities of the present document are applicable.

[021] Figure 4 shows an example of a figure decoding procedure.

[022] Figure 5 shows an example of a figure encoding procedure.

[023] Figure 6 shows an example of an interprediction-based video/image coding method.

[024] Figure 7 shows an overview of an interpredictor in a coding apparatus.

[025] Figure 8 shows an example of an interprediction-based video/image decoding method.

[026] Figure 9 shows an overview of an interpredictor in a decoding apparatus.

[027] Figures 10 and 11 respectively show general examples of a video/image coding method and a related component in accordance with an embodiment of the present disclosure.

[028] Figures 12 and 13 respectively show general examples of a video/image decoding method and a related component in accordance with an embodiment of the present disclosure.

[029] Figure 14 shows an example of a content streaming system to which the embodiment of the present disclosure can be applied.

DESCRIPTION OF EXEMPLIFYING MODALITIES

[030] The disclosure of this document can be modified in various ways and specific embodiments thereof will be described and illustrated in the drawings. Terms used herein are used only to describe specific embodiments, but are not intended to limit the method disclosed herein. An expression of a singular number includes an expression of “at least one” as long as it is clearly read differently. Terms such as “include” and “have” are intended to indicate that the features, numbers, steps, operations, elements, components or combinations thereof used in the document exist and it should be understood that the possibility of the existence or addition of a or more different features, numbers, steps, operations, elements, components or combinations thereof are not excluded.

[031] Furthermore, each configuration of the drawings described in this document is an independent illustration to explain functions such as characteristics that are different from each other, and does not mean that each configuration is implemented by mutually different hardware or software. For example, two or more configurations can be combined to form a configuration, and a configuration can also be divided into multiple configurations. Without departing from the essence of the disclosed method of the present document, embodiments in which the configurations are combined and/or separate are included in the scope of the disclosure of the present document.

[032] This document refers to video/image coding. For example, a method/embodiment disclosed herein may be applied to a method disclosed in a versatile video coding (VVC) standard. Furthermore, the method/embodiment disclosed herein can be applied to a method disclosed in an Essential Video Coding (EVC) standard, AOMedia Video 1 (AV1) standard, 2nd generation audio and video coding standard (AVS2) , or a next-generation video/image coding standard (e.g. H.267, H.268, etc.).

[033] In this document, a video may refer to a series of images over time. A figure refers, in general, to the unit that represents an image in a particular time frame, and a slice/tile refers to the unit that constitutes a part of the figure in terms of coding. A slice/tile can include one or more coding tree units (CTUs). A figure can consist of one or more slices/tiles. A figure can consist 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 on a tile in a figure). A tile can be partitioned into multiple bricks, each of which consists of one or more rows of CTUs in the tile. A tile that is not partitioned into multiple tiles can also be referred to as a brick. A brick scan is a specific sequential ordering of CTUs that partition a figure where CTUs are ordered consecutively in a raster scan of the CTU in a brick, bricks in a tile are ordered consecutively in a raster scan of the tile's bricks, and the tiles in a figure are ordered consecutively in a raster scan of the figure's tiles. A tile is a rectangular region of CTUs in a particular tile column and a particular tile row in a figure. The tile column is a rectangular region of CTUs having a height equal to the figure height and a width specified by syntax elements in the figure parameter set. The tile row is a rectangular region of CTUs having a height specified by syntax elements in the figure parameter set and a width equal to the figure width). A tile scan is a specific sequential ordering of CTUs partitioning a figure where CTUs are ordered consecutively in a raster scan of the CTU in a tile while tiles in a figure are ordered consecutively in a raster scan of the figure's tiles. A slice includes an integer number of bricks of a figure that can be uniquely contained in a single NAL unit. A slice can consist of a series of complete tiles or just a consecutive sequence of complete bricks of a tile. In this document, a tile and slice group can be used interchangeably. For example, in the present document, a tile group/tile group header may be referred to as a slice/slice header.

[034] A pixel or a pel can mean a smaller unit that constitutes a figure (or image). Similarly, ‘sample’ can be used as a term corresponding to a pixel. A swatch may, in general, represent a pixel or a value of a pixel, and may represent only a pixel/pixel value of a luma component or only a pixel/pixel value of a chroma component.

[035] A unit may represent a basic image processing unit. The unit may include at least one of a specific region of the figure and information related to the region. A unit may include one luma block and two chroma blocks (e.g. cb, cr). The unit can be used interchangeably with terms such as block or area in some cases. In a general case, an M*N block may include samples (or sample arrays) or a set (or array) of M column and N row transform coefficients. Alternatively, the sample may mean a pixel value in the spatial domain, and when that pixel value is transformed to the frequency domain, it may mean a transform coefficient in the frequency domain.

[036] Unit can be used interchangeably with the term, as a block or an area in some cases. Generally, an MxN block can represent samples composed of M columns and N rows or a set of transform coefficients. The sample can generally represent a pixel or a pixel value and can also represent just the pixel/pixel value of a luma component and also represent just the pixel/pixel value of a chroma component. Sample can be used as the term corresponding to a pixel or a pel configuring an image (or image).

[037] Various modalities related to video/image coding are presented in this document, and the modalities may be combined with each other except where stated otherwise.

[038] In this document, technical resources individually explained in drawings can be individually implemented or simultaneously implemented.

[039] Hereinafter, embodiments of the present document will be described in detail with reference to the attached drawings. Furthermore, similar reference numerals are used to indicate similar elements throughout the drawings, and the same descriptions on similar elements may be omitted.

[040] Figure 1 illustrates an example of a video/image coding system to which the modalities of the present document can be applied.

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

[042] The source device may include a video source, an encoding apparatus and a transmitter. The receiving device may include a receiver, a decoding apparatus, and a processor. The encoding apparatus may be called a video/image encoding apparatus, and the decoding apparatus may be called a video/image decoding apparatus. The transmitter may be included in the coding apparatus. The receiver may be included in the decoding apparatus. The renderer can include a canvas, and the canvas can be configured as a separate device or an external component.

[043] The video source can acquire video/image through a process of capturing, synthesizing or generating the video/image. The video source may include a video/image capture device and/or a video/image generating device. The video/image capture device may include, for example, one or more cameras, video/image files including previously captured video/images, and the like. The video/image generating device may include, for example, computers, tablets and smart phones and may (electronically) generate video/images. For example, a virtual video/image can be generated using a computer or similar. In this case, the video/image capture process can be replaced by a related data generation process.

[044] The encoding apparatus can encode input video/image. The coding apparatus can perform a series of procedures such as prediction, transform, and quantization for compression and coding efficiency. The encoded data (encoded video/image information) can be output in the form of a bit stream.

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

[046] The decoding device can decode the video/image by performing a series of procedures such as dequantization, inverse transform and prediction corresponding to the operation of the coding device.

[047] The renderer can render the decoded video/image. The rendered video/image can be displayed on the screen.

[048] In this document, the term “/” “and” should be interpreted to indicate “and/or.” For example, the expression “A/B” can mean “A and/or B.” Furthermore, “A, B” can mean “A and/or B”. Furthermore, “A/B/C” can mean “at least one of A, B and/or C”. Furthermore, “A/B/C” can mean “at least one of A, B and/or C”.

[049] Furthermore, in the document, the term “or” must be interpreted to indicate “and/or”. For example, the expression “A or B” may comprise 1) A only, 2) B only, and/or 3) A and B. In other words, the term “or” in this document should be interpreted to indicate “additionally or alternatively ”.

[050] Furthermore, the parentheses used in this specification may mean “for example”. Specifically, in the case where “prediction (intraprediction)” is expressed, it can be indicated that “intraprediction” is proposed as an example of “prediction”. In other words, the term “prediction” in the present specification is not limited to “intraprediction”, and it may be indicated that “intraprediction” is proposed as an example of “prediction”. Furthermore, even in the case where “prediction (i.e., intraprediction)” is expressed, it can be indicated that “intraprediction” is proposed as an example of “prediction”.

[051] Figure 2 is a diagram that schematically illustrates the configuration of a video/image coding apparatus to which the modalities of the present document can be applied. Hereinafter, what is referred to as a video coding apparatus may include an image coding apparatus.

[052] Referring to Figure 2, the coding apparatus 200 may include and be configured with 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 may include an interpredictor 221 and an intrapredictor 222. The residual processor 230 may include a transformer 232, a quantizer 233, a dequantizer 234, and an inverse transformer 235. The residual processor 230 may further include a subtractor 231 The adder 250 may be called a rebuilder or a rebuilt block generator. Image partitioner 210, predictor 220, residual processor 230, entropy encoder 240, adder 250, and filter 260, which have been described above, may be configured by one or more hardware components (e.g., sets of encoder chips or processors) according to one embodiment. Furthermore, memory 270 may include a temporary decoded picture store (DPB), and may also be configured by a digital storage medium. The hardware component may further include memory 270 as an internal/external component.

[053] The image partitioner 210 may divide an input image (or, image, frame) input to the encoding apparatus 200 into one or more processing units. As an example, the processing unit may be called the coding unit (CU). In this case, the coding unit can be divided recursively according to a Quad-tree binary tree ternary tree (QTBTTT) structure of a coding tree unit (CTU) or the largest coding unit (LCU). For example, a coding unit may be divided into a plurality of coding units of a deeper depth based on a quadruple tree structure, a binary tree structure, and/or a ternary tree structure. In this case, for example, the quadruple tree structure is applied first and the binary tree structure and/or the ternary tree structure can be applied later. Alternatively, the binary tree structure can also be applied first. A coding procedure in accordance with this document may be carried out based on a final coding unit that is not further divided. In this case, based on the coding efficiency according to image characteristics or the like, the maximum coding unit can be directly used as the final coding unit, or as necessary, the coding unit can be recursively divided into coding units of a deeper depth, such that an optimally sized encoding unit can be used as the final encoding unit. Here, the coding procedure may include a procedure such as prediction, transform and reconstruction to be described later. As another example, the processing unit may further include a prediction unit (PU) or a transform unit (TU). In this case, each prediction unit and transform unit can be divided or partitioned from the aforementioned final coding unit. The prediction unit may be a sample prediction unit and the transform unit may be a unit for inducing a transform coefficient and/or a unit for inducing a residual signal of the transform coefficient.

[054] The coding apparatus 200 may subtract the prediction signal (predicted block, prediction sample array) emitted from the interpredictor 221 or the intrapredictor 222 from the input image signal (original block, original sample array ) to generate a residual signal (residual block, residual sample array), and the generated residual signal is transmitted to transformer 232. In this case, as illustrated, a unit for subtracting the prediction signal (prediction block, sample array from prediction) from an input image signal (original block, original sample array) in the encoder 200 may be referred to as a subtractor 231. The predictor 220 may perform prediction on a processing target block (hereinafter referred to as a block current) and generate a predicted block including prediction samples for the current block. The predictor 220 can determine whether intraprediction or interprediction is applied on units of a current block or CU. The predictor 220 may generate various types of prediction information, such as prediction mode information, and transmit the generated information to the entropy encoder 240, as will be described below in the description of each prediction mode. The prediction information may be encoded by the entropy encoder 240 and output in the form of a bit stream.

[055] The intrapredictor 222 can predict a current block with reference to samples within a current image. The referenced samples can be located neighboring the current block, or they can also be located outside the current block according to the prediction mode. The prediction modes in intraprediction may include a plurality of non-directional modes and a plurality of directional modes. The non-directional mode may include, for example, a DC mode or a planar mode. The directional mode may include, for example, 33 directional prediction modes or 65 directional prediction modes according to the fine degree of the prediction direction. However, this is illustrative and directional prediction modes that are more or less than the above number can be used according to the configuration. The intrapredictor 222 may also determine the prediction mode applied to the current block using the prediction mode applied to the neighboring block.

[056] The interpredictor 221 may induce a block from the predicted current block based on a reference block (reference sample matrix) specified by a motion vector in a reference image. At this time, in order to decrease the amount of motion information transmitted in interprediction mode, motion information can be predicted in units of a block, a sub-block or a sample based on the correlation of motion information between the blocks neighbor and current block. The motion information may include a motion vector and a reference image index. The motion information may further include interprediction direction information (L0 prediction, L1 prediction, Bi prediction, or the like). In the case of interprediction, the neighboring block may include a spatial neighboring block existing in the current image and a temporal neighboring block existing in the reference image. The reference image including the reference block and the reference image including the temporal neighboring block may also be the same as each other and may also be different from each other. The temporal neighbor block may be called a collocated reference block, a collocated CU (colCU) or the like, and the reference image including the temporal neighbor block may also be called a collocated image (colPic). For example, interpredictor 221 may configure a candidate list of motion information based on neighboring blocks and generate information indicating which candidate is used to derive the motion vector and/or reference image index of the current block. Interprediction can be performed based on various prediction modes, and for example, in the case of an omit mode and a merge mode, the interpredictor 221 can use the movement information of the neighboring block as the movement information of the current block. . In case of skip mode, the residual signal cannot be transmitted unlike in melting mode. A motion vector prediction (MVP) mode can indicate the motion vector of the current block by using the motion vector of the neighboring block as a motion vector predictor and signaling a motion vector difference.

[057] The predictor 220 can generate a prediction signal based on various prediction methods that will be described below. For example, the predictor 220 may apply intraprediction or interprediction to predict a block and may simultaneously apply intraprediction and interprediction. This can be termed as combined inter- and intra-prediction (CIIP). Furthermore, the predictor may be based on an intra block copy (IBC) prediction mode or based on a palette mode for single-block prediction. IBC prediction mode or palette mode can be used for image/video coding of content such as games, for example, on-screen content coding (SCC). IBC basically performs prediction on a current figure, but it can be performed similarly to interprediction by the fact that a reference block is derived on the current figure. That is, IBC can use at least one of the interprediction techniques described in this document. Palette mode can be viewed as an example of intracoding or intraprediction. When palette mode is applied, a sample value in the figure can be flagged based on information about the palette table and palette index.

[058] The prediction signal generated by the predictor (including the interpredictor 221 and/or the intrapredictor 222) can be used to generate a reconstructed signal or can be used to generate a residual signal.

[059] Transformer 232 can generate transform coefficients by applying a transform technique to the residual signal. For example, the transform technique may include at least one of a discrete cosine transform (DCT), a discrete sine transform (DST), a graph-based transform (GBT), or a conditionally nonlinear transform (CNT). In this document, GBT refers to the transformation obtained from a graph by expressing relationship information between pixels in the graph. CNT refers to the transformation obtained based on a prediction signal generated using all previously reconstructed pixels. Likewise, the transformation process can be applied to a block of pixels having the same size as a square or can be applied to a block of a variable size that is not a square.

[060] The quantizer 233 quantizes the transform coefficients and transmits them to the entropy encoder 240, and the entropy encoder 240 encodes the quantized signal (information about the quantized transform coefficients) and outputs the encoded signal as a bit stream . Information about quantized transform coefficients can be referred to as residual information. The quantizer 233 can rearrange the quantized transform coefficients in the block in the form of a one-dimensional vector based on a coefficient sweep order and can generate information about the transform coefficients in the quantized transform coefficients in the form of a one-dimensional vector.

[061] The entropy encoder 240 can 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 encode information necessary for video/image reconstruction (e.g., values of syntax elements, etc.) in addition to the quantized transform coefficients together or separately. Encoded information (e.g., encoded video/image information) may be transmitted or stored in units of a network abstraction layer (NAL) unit in the form of a bit stream. The video/image information may further include information about various parameter sets, such as an adaptation parameter set (APS), a figure parameter set (PPS), a sequence parameter set (SPS), or a set of video parameters (VPS). Likewise, video/image information may also include general restriction information. In this document, information and/or syntax elements transmitted/signaled from the encoding apparatus to the decoding apparatus may be included in video/image information. Video/image information can be encoded using the encoding procedure described above and included in the bit stream. The bit stream can be transmitted over a network or can be stored on digital storage media. Herein, the network may include a broadcasting network and/or a communication network, and the digital storage media may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD and SSD. A transmission unit (not shown) and/or a storage unit (not shown) for transmitting or storing a signal emitted from the entropy encoder 240 may be configured as internal/external elements of the coding apparatus 200, or the unit transmission code may be included in the entropy encoder 240.

[062] The quantized transform coefficients output from the quantizer 233 can be used to generate a prediction signal. For example, the residual signal (residual block or residual samples) can be reconstructed by applying dequantization and inverse transform to the quantized transform coefficients via the dequantizer 234 and the inverse transform unit 235. The adder 250 can add the reconstructed residual signal to the prediction signal output from interpredictor 221 or intrapredictor 222 to generate a reconstructed signal (reconstructed figure, reconstructed block, reconstructed sample array). When there is no residual for the processing target block, such as when skip mode is applied, the predicted block can be used as a reconstructed block. The adder 250 may be referred to as a restoration unit or a restoration block generator. The generated reconstructed signal can be used for intra-prediction of a next processing target block in the current figure, or it can be used for inter-prediction of the next figure after being filtered as described below.

[063] However, a chroma scaling luma mapping (LMCS) can be applied during a figure encoding and/or reconstruction process.

[064] Filter 260 can improve subjective/objective image quality by applying filtering to the reconstructed signal. For example, filter 260 may generate a modified reconstructed figure by applying various filtering methods to the reconstructed figure and storing the modified reconstructed figure in memory 270, specifically, in a DPB of memory 270. The various filtering methods may include, e.g. example, deblocking filtering, an adaptive sample shift, an adaptive loop filter, a bilateral filter, and the like. The filter 260 may generate various types of filtering-related information and transfer the generated information to the entropy encoder 240 as described later in the description of each filtering method. Filtering-related information may be encoded by entropy encoder 240 and output in the form of a bit stream.

[065] The modified reconstructed figure transmitted to memory 270 can be used as a reference figure in the interpredictor 221. When the interprediction is applied through the encoding apparatus, prediction incompatibility between the encoding apparatus 200 and the decoding apparatus may be avoided and coding efficiency can be improved.

[066] The DPB of memory 270 may store the modified reconstructed figure for use as the reference figure in interpredictor 221. Memory 270 may store the motion information of a block from which the motion information in the current figure is derived. (or encoded) and/or the movement information of the blocks in the figure that have already been reconstructed. The stored motion information can be transferred to the interpredictor 221 and used as the spatial neighboring block motion information or the temporal neighboring block motion information. Memory 270 may store the reconstructed samples of reconstructed blocks in the current figure and may transfer the reconstructed samples to the intrapredictor 222.

[067] Figure 3 is a diagram to schematically explain the configuration of a video/image decoding apparatus to which the embodiments of the present document can be applied.

[068] Referring to Figure 3, the decoding apparatus 300 may include and configured with an entropy decoder 310, a residual processor 320, a predictor 330, an adder 340, a filter 350, and a memory 360. The predictor 330 may include an interpredictor 331 and an intrapredictor 332. The residual processor 320 may include a dequantizer 322 and an inverse transformer 321. The entropy decoder 310, the residual processor 320, the predictor 330, the adder 340, and the filter 350, which have been described previously, may be configured by one or more hardware components (e.g., decoder chipsets or processors) according to one embodiment. Furthermore, the memory 360 may include a decoded picture buffer (DPB) and may be configured by a digital storage medium. The hardware component may additionally include memory 360 as an internal/external component.

[069] When the bit stream including video/image information is input, the decoding apparatus 300 may reconstruct the image in response to a process in which the video/image information is processed in the encoding apparatus illustrated in Figure 2 For example, the decoding apparatus 300 may derive the units/blocks based on the block partition-related information acquired from the bit stream. The decoding apparatus 300 may perform decoding using a processing unit applied to the encoding apparatus. Therefore, the processing unit for decoding may be, for example, an encoding unit, and the encoding unit may be partitioned according to the quaternary tree structure, binary tree structure and/or the ternary tree structure of the unit. coding tree or maximum coding unit. One or more transform units may be derived from the coding unit. Furthermore, the reconstructed image signal decoded and output through the decoding apparatus 300 can be reproduced via a playback apparatus.

[070] The decoding apparatus 300 can receive a signal emitted from the encoding apparatus of Figure 2 in the form of a bit stream, and the received signal can be decoded through the entropy decoder 310. For example, the decoder entropy 310 may analyze the bit stream to derive information (e.g., video/image information) necessary for image reconstruction (or figure reconstruction). The video/image information may additionally include information about various parameter sets such as an adaptation parameter set (APS), a figure parameter set (PPS), a sequence parameter set (SPS), or a parameter set video (VPS). Furthermore, the video/image information may additionally include restriction information. The decoding apparatus may further decode the figure based on information in the parameter set and/or general constraint information. The signaled/received information and/or syntax elements described later herein may be decoded to decode the decoding procedure and obtained from the bit stream. For example, the entropy decoder 310 decodes the information in the bit stream based on a coding method such as an exponential Golomb coding, context-adaptive variable length coding (CAVLC), or context-adaptive arithmetic coding (CABAC). , and output syntax elements required for image reconstruction and quantized values of transform-to-residual coefficients. More specifically, the CABAC entropy decoding method may receive a bin corresponding to each syntax element in the bitstream, determine a context model using decoding target syntax element information from a decoding target block, or information from a symbol/bin decoded in a previous stage, and perform an arithmetic decoding on the bin, predicting a probability of occurrence of a bin according to the determined context model, and generating a symbol corresponding to the value of each syntax element . In this case, the CABAC entropy decoding method can update the context model using the information from the decoded symbol/bin to a context model of a next symbol/bin after determining the context model. The prediction-related information between the information decoded by the entropy decoder 310 may be provided to the predictor (the interpredictor 332 and the intrapredictor 331), and residual values at which entropy decoding was performed in the entropy decoder 310, i.e., the quantized transform coefficients and related parameter information may be input into the residual processor 320.

[071] The residual processor 320 can derive a residual signal (residual block, residual samples, or residual sample matrix). Likewise, information about filtering among the information decoded by entropy decoder 310 may be provided to filter 350. However, the receiving unit (not shown) for receiving a signal emitted from the encoding apparatus may be further configured as an element internal/external decoding apparatus 300, or the receiving unit may be a component of the entropy decoder 310. However, the decoding apparatus according to the present document may be referred to as a video/image/picture decoding apparatus , and the decoding apparatus can be divided 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 dequantizer 321, the inverse transformer 322, the adder 340, the filter 350, the memory 360, an interpredictor 332, and an intrapredictor. 331.

[072] The dequantizer 321 can dequantize the quantized transform coefficients to output the transform coefficients. The dequantizer 321 can rearrange the quantized transform coefficients into a two-dimensional block shape. In this case, the rearrangement can be performed based on the coefficient scanning order performed by the coding apparatus. The dequantizer 321 may perform a dequantization for the quantized transform coefficients using a quantization parameter (e.g., quantization step size information) and acquire transform coefficients.

[073] The inverse transformer 322 inversely transforms the transform coefficients to acquire the residual signal (residual block, residual sample matrix).

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

[075] In this document, the quantized transform coefficient and the transform coefficient may be referred to as a transform coefficient and a scaled transform coefficient, respectively. In this case, the residual information may include information about transform coefficients, and the information about transform coefficients may be signaled through residual encoding syntax. Transform coefficients can be derived based on the residual information (or information about the transform coefficients), and scaled transform coefficients can be derived by inverse transforming (scaling) on the transform coefficients. Residual samples can be derived based on inverse transform (transform) of the scaled transform coefficients. This may also be applied/expressed elsewhere in this document.

[076] The predictor 330 can perform the prediction of the current block and generate a predicted block including the prediction samples from the current block. The predictor may determine whether intra-prediction is applied or inter-prediction is applied to the current block based on information in the prediction emitted from the entropy decoder 310 and determine a specific intra-/inter-prediction mode.

[077] The predictor 330 may generate a prediction signal based on various prediction methods described below. For example, the predictor may apply intraprediction or interprediction to predict a block, and may simultaneously apply intraprediction and interprediction. This can be called combined inter- and intra-prediction (CIIP). Furthermore, the predictor can be based on an intra block copy (IBC) prediction mode or based on a palette mode for predicting a block. IBC prediction mode or palette mode can be used for image/video coding of content such as games, for example, screen content coding (SCC). IBC can basically perform prediction on the current figure, but it can be performed in a similar way to interprediction in that a reference block is derived on the current figure. That is, the IBC may use at least one of the interprediction techniques described in this document. Palette mode can be considered as an example of intracoding or intraprediction. When palette mode is applied, information about the palette table and palette index can be included in the video/image information and flagged.

[078] The intrapredictor 331 can predict the current block by referring to the samples in the current figure. The referred samples may be located in the vicinity of the current block or may be located separate from the current block according to the prediction mode. In intraprediction, the prediction modes may include a plurality of non-directional modes and a plurality of directional modes. The intrapredictor 331 may determine the prediction mode to be applied to the current block using the prediction mode applied to the neighboring block.

[079] Interpredictor 332 may derive a predicted block for the current block based on a reference block (reference sample matrix) specified by a motion vector in a reference figure. In this case, to reduce the amount of motion information being transmitted in interprediction mode, motion information can be predicted in unit blocks, sub-blocks, or samples based on the correlation of motion information between the neighboring block and the current block. The motion information may include a motion vector and a reference figure index. The motion information may additionally include the interprediction direction information (L0 prediction, L1 prediction, Bi prediction, and the like). In the case of interprediction, the neighboring block may include a spatial neighboring block existing in the current figure and a temporal neighboring block present in the reference figure. For example, the interpredictor 332 may construct a candidate list of motion information based on neighboring blocks and derive a current block motion vector and/or a reference figure index based on the received candidate selection information. Interprediction may be performed based on various prediction modes, and information about the prediction may include information indicating an interprediction mode for the current block.

[080] The adder 340 can generate a reconstructed signal (reconstructed figure, reconstructed block or reconstructed sample matrix) by summing the obtained residual signal to the prediction signal (predicted block or predicted sample matrix) emitted from the predictor (including the interpredictor 332 and/or the intrapredictor 331). If there is no residue for the processing target block, such as a case where an omit mode is applied, the predicted block can be used as the reconstructed block.

[081] Adder 340 can be referred to as a rebuilder or a reconstructed block generator. The reconstructed signal generated can be used for intraprediction of a next block that will be processed in the current figure, and as described later, it can also be output through filtering, or it can also be used for interprediction of a next figure.

[082] However, a luma mapping with chroma scaling (LMCS) can also be applied in the figure decoding process.

[083] Filter 350 can improve subjective/objective image quality by applying filtering to the reconstructed signal. For example, filter 350 may generate a modified reconstructed figure by applying various filtering methods to the reconstructed figure and storing the modified reconstructed figure in memory 360, specifically, in a DPB of memory 360. The various filtering methods may include, e.g. example, deblocking filtering, an adaptive sample shift, an adaptive loop filter, a bilateral filter, and the like.

[084] The reconstructed (modified) figure stored in the DPB of memory 360 can be used as a reference figure in interpredictor 332. Memory 360 can store the motion information of the block from which the motion information in the current figure is derived (or decoded) and/or the movement information of the blocks in the figure that have already been reconstructed. The stored motion information may be transferred to the interpredictor 332 to be used as the spatial neighbor block motion information or the temporal neighbor block motion information. The memory 360 may store the reconstructed samples of reconstructed blocks in the current figure and transfer the reconstructed samples to the intrapredictor 331.

[085] In the present document, the embodiments described in the filter 260, the interpredictor 221 and the intrapredictor 222 of the coding apparatus 200 can be applied equally or correspond to the filter 350, the interpredictor 332 and the intrapredictor 331.

[086] However, the video/image coding method according to the present document can be carried out based on the following partitioning structure. Specifically, prediction procedures, residual processing (transformed (inverse) and (de)quantization), syntax element encoding and filtering described previously can be performed based on CTU and CU (and/or TU and PU) derived with based on the partitioning structure. A block partitioning procedure may be performed by the image partitioner 210 of the encoding apparatus described above, and partitioning-related information may be processed (encoding) by the entropy encoder 240, and may be transferred to the decoding apparatus in the form of a stream of bits. The entropy decoder 310 of the decoding apparatus may derive the block partitioning structure of the current figure based on the partitioning-related information obtained from the bit stream, and based on this, may perform a series of procedures (e.g., prediction, residual processing, block/figure reconstruction, loop filtering, and the like) for image decoding. The CU size and TU size may be equal to each other, or a plurality of TUs may be present in a CU region. However, the CU size can generically represent a luma component (sample) coding block (CB) size. The TU size can generically represent a luma component (sample) transform block (TB) size. A chroma component (sample) CB or TB size can be derived based on the luma component (sample) CB or TB size according to a component ratio according to a color format (chroma format, for example, 4:4:4, 4:2:2, 4:2:0, and similar) of a figure/image. The size of TU can be derived based on maxTbSize. For example, if the size of CU is greater than maxTbSize, a plurality of TUs (TBs) of maxTbSize can be derived from CU, and the transform/inverse transform can be performed in the unit of the TU (TB). Furthermore, for example, in the case where intraprediction is applied, the mode/type of intraprediction can be derived in the CU (or CB) unit, and the derivation of a neighboring reference sample and prediction sample generation procedures can be performed in the TU (or TB) unit. In this case, one or a plurality of TUs (or TBs) may be present in a CU (or CB) region, and in this case, the plurality of TUs (or TBs) may share the same intraprediction mode/type.

[087] Furthermore, in video/image coding according to this document, an image processing unit may have a hierarchical structure. A figure can be partitioned into one or more tiles, bricks, slices and/or groups of tiles. A slice can include one or more bricks. A brick can include one or more rows of CTU in a tile. The slice can include an integer number of bricks from a figure. A tile group can include one or more tiles. A tile can include one or more CTUs. The CTU can be partitioned into one or more CUs. A tile represents a rectangular region of CTUs in a particular tile column and a particular tile row in a figure. A tile group can include an integer number of tiles according to a tile raster scan in the figure. 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 apparatus has a multi-core processor, encoding/decoding processes for the tiles, slices, bricks and/or tile groups can be processed in parallel. In this document, the slice or the group of tiles can be used interchangeably. That is, a tile group header can be termed as a slice header. Herein, the slice may have one of the slice types including intra slice (I), predictive slice (P), and bipredictive slice (B). In I-slice prediction blocks, interprediction may or may not be used, and only intraprediction may be used. Of course, even in this case, signaling can be performed by encoding the original sample value without prediction. Regarding blocks in P-slice, intra-prediction or inter-prediction can be used, and in case of using inter-prediction, only uni-prediction can be used. However, regarding blocks in B-slice, intra-prediction or inter-prediction can be used, and in case of using inter-prediction, even Bi-prediction can be maximally used.

[088] The coding apparatus may determine the maximum and minimum tile/tile group, brick, slice, and coding unit sizes in consideration of coding efficiency or parallel processing, or in accordance with characteristics (e.g., resolution) of a video image, and information for the same or information capable of inducing them may be included in the bit stream.

[089] The decoding apparatus can obtain information representing the tile/group of tiles, brick and slice of the current figure, and whether the CTU in the tile has been partitioned into a plurality of coding units. By having this information obtained (transmitted) only under a specific condition, efficiency can be improved.

[090] However, as described previously, a figure may include a plurality of slices, and a slice may include a slice header and slice data. In this case, a figure header may further be added to a plurality of slices (a slice header and a slice data set) in a figure. The slice header (figure header syntax) can include information/parameters commonly applicable to the figure. The slice header (slice header syntax) can include information/parameters that can be commonly applied to the slice. An adaptation parameter set (APS) or a figure parameter set (PPS) may include information/parameters that can be commonly applied to one or more slices or figures. A sequence parameter set (SPS) may include information/parameters that can be commonly applied to one or more sequences. A video parameter set (VPS) can include information/parameters that can be commonly applied to multiple layers. A decoding parameter set (DPS) can include information/parameters that can be commonly applied to the overall video. The DPS may include information/parameters related to the concatenation of a coded video sequence (CVS).

[091] A high-level syntax (HLS) in the present disclosure includes at least one of APS syntax, PPS syntax, SPS syntax, VPS syntax, DPS syntax and slice header syntax .

[092] Additionally, for example, information about partitioning and configuration, and so on, of a tile/group of tiles/brick/slice can be configured in a coding apparatus based on high-level syntax and can then be be delivered (or transferred) to a decoding device in a bitstream format.

[093] A figure can 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 region of a figure. A tile can be partitioned into one or more bricks, and each brick can be configured by multiple CTU rows. A tile that is not partitioned into a plurality of bricks may also be referred to as a brick. However, a brick being a subset of a tile is not referred to as a tile. A slice can include multiple tiles or multiple bricks of a tile.

[094] Figure 4 shows an example of a figure decoding procedure.

[095] In image/video coding, a figure that configures an image/video can be encoded/decoded according to a decoding order. A picture order that corresponds to an output order of a decoded picture can be configured differently than the decoding order. And, when performing interprediction based on the configured figure order, forward prediction as well as reverse prediction can be performed.

[096] Figure 4 shows a general example of a figure decoding procedure to which embodiments of the present disclosure can be applied. In Figure 4, S400 may be realized by the entropy decoder 310 of the decoding apparatus that was described above in Figure 3, S410 may be realized by the predictor 330, S420 may be realized by the residual processor 320, S430 may be realized by the adder 340, and S440 may be performed by filter 350. S400 may include an information decoding procedure that is described in the present specification, S410 may include an inter/intraprediction procedure that is described in the present specification, S420 may include a processing procedure residual which is described in the present specification, S430 may include a block/figure reconstruction procedure that is described in the present specification, and S440 may include a loop filtering procedure that is described in the present specification.

[097] Referring to Figure 4, as previously described in Figure 3, the figure decoding procedure may generally include a procedure for obtaining image/video information (S400) from a bit stream (through decoding) , an image reconstruction procedure (S410 to S430) and a loop filtering procedure (S440) for the reconstructed figure. The image reconstruction procedure can be performed based on prediction samples and residual samples that are obtained by performing the inter/intraprediction procedure (S410) and the residual processing procedure (S420, dequantization procedures and inverse transforms in coefficients quantized transforms). By performing a loop filtering procedure on the reconstructed figure that is generated by performing the figure reconstruction procedure, a modified reconstructed figure can be generated, and the modified reconstructed figure can be output as a decoded figure, which is then stored in a decoding figure buffer or memory 360 of the decoding apparatus so that it is used as a reference figure during an interprediction procedure when performing a decoding of a figure in a later process. In some cases, the loop filtering procedure can be omitted. And in this case, the reconstructed figure may be output as the decoded figure, which is then stored in a decoding figure buffer or memory 360 of the decoding apparatus so that it is used as a reference figure during a decoding procedure. interprediction when performing a decoding of a figure in a later process. As described previously, the loop filtering procedure (S440) may include a deblocking filtering procedure, an adaptive sample shift (SAO) procedure, an adaptive loop filtering (ALF) procedure, and/or a two-sided filter procedure. , and so on, and part or all of the loop filtering procedure can be omitted. Additionally, one or part of the deblocking filtering procedure, sample adaptive offset (SAO) procedure, adaptive loop filter (ALF) procedure, and bilateral filter procedure may be applied sequentially, or all of the deblocking filtering procedure, procedure sample adaptive offset (SAO), adaptive loop filter (ALF) procedure, and bilateral filter procedure can be applied sequentially. For example, after the deblocking filtering procedure is applied to a reconstructed figure, the SAO procedure can be performed. Alternatively, for example, after the deblocking filtering procedure is applied to a reconstructed figure, the ALF procedure can be performed. This can also be carried out on a coding device.

[098] Figure 5 shows an example of a figure encoding procedure.

[099] Figure 5 shows a general example of a figure encoding procedure to which an embodiment of the present disclosure can be applied. In Figure 5, S500 may be realized by the predictor 220 of the coding apparatus that was described above in Figure 2, S510 may be realized by the residual processor 230, and S520 may be realized by the entropy encoder 240. S500 may include an inter/ intraprediction that is described in the present specification, S610 may include a residual processing procedure that is described in the present specification and S520 may include an information coding procedure that is described in the present specification.

[0100] Referring to Figure 5, as previously described in Figure 2, the figure encoding procedure may generally include an encoding information procedure for figure reconstruction (e.g., prediction information, residual information, partitioning information , and so on) and output the encoded information in a bitstream format, as well as a procedure for generating a reconstructed figure for a current figure and a procedure for applying loop filtering to the reconstructed figure (optional). The coding apparatus may derive residual samples (which are modified) from quantized transform coefficients via the dequantizer 234 and inverse transformer 235, and then the coding apparatus may generate a reconstructed figure based on the prediction samples, which are the output of S500, and the residual (modified) samples. The reconstructed figure that is generated as described above may be the same as the reconstructed figure described above that is generated in the decoding apparatus. A modified reconstructed figure can be generated by performing a loop filtering procedure on the reconstructed figure, which is then stored in a decoding figure buffer or memory 270 of the decoding apparatus. And, just as in the decoding apparatus, the modified reconstructed figure can be used as a reference figure during an interprediction procedure when encoding a figure. As described previously, in some cases, part or all of the loop filtering procedure may be omitted. When the flower loop filtering procedure is carried out, information (parameter) related information (loop) can be encoded in the entropy encoder 240 and then transmitted in a bit stream format, and the decoding apparatus can perform the loop filtering procedure using the same method as the coding device based on information related to filtering.

[0101] By carrying out the previously described loop filtering procedure, noise that occurs when encoding moving image/figure, such as blocking artifact and ringing artifact, can be reduced, and subjective/objective visual quality can be reduced. be improved. Additionally, by having both the encoding apparatus and the decoding apparatus perform the loop filtering procedure, the encoding apparatus and the decoding apparatus can derive the same prediction result, increase the reliability in figure encoding, and reduce the size (or amount) of data that must be transmitted for figure encoding.

[0102] As described previously, the figure reconstruction procedure can be performed on the decoding apparatus as well as on the encoding apparatus. A reconstructed block can be generated for each block unit based on intraprediction/interprediction, and a reconstructed figure including reconstructed blocks can be generated. When a current figure/slice/tile group is a figure/slice/tile group I, the blocks included in the current figure/slice/tile group can be reconstructed based on intraprediction only. However, when the current figure/slice/tile group is a P or B figure/slice/tile group, the blocks included in the current figure/slice/tile group can be reconstructed based on intraprediction or interprediction. In this case, interprediction can be applied to part of the blocks in the current figure/slice/tile group, and an intraprediction can be applied to the remaining blocks. Color components of a figure may include a luma component and a chroma component. And, except where explicitly limited (or restricted) in the present specification, the methods and modalities that are proposed in the present specification can be applied to the luma component and the chroma component.

[0103] However, a video/image coding procedure that relies on interprediction may generally include, for example, the following.

[0104] Figure 6 shows an example of an interprediction-based video/image coding method, and Figure 7 shows an overview of an interpredictor in a coding apparatus.

[0105] Referring to Figure 6 and Figure 7, the coding apparatus performs interprediction on a current block (S600). The coding apparatus may derive an interprediction mode and motion information from the current block, and generate prediction samples from the current block. In this document, the procedures for determining the interprediction mode, deriving motion information, and generating prediction samples may all be performed simultaneously, or any of the aforementioned procedures may be performed before other procedures. For example, the interpredictor 221 of the coding apparatus may include a prediction mode determiner 221_1, a motion information derivator 221_2, and a prediction sample derivator 221_3. The prediction mode determiner 221_1 can determine a prediction mode for the current block, the motion information deriver 221_2 can derive motion information from the current block, and the prediction sample deriver 221_3 can derive prediction samples from the current block. For example, the coding device interpredictor can search for a block that is similar to the current block in a predetermined region (search region) of reference pictures through motion estimation, and then the coding device interpredictor can derive a reference block that is equal to or less than a predetermined reference standard. Based on this difference, a reference figure index that indicates a reference figure where the reference block is situated can be derived, and a motion vector can be derived based on a position difference between the reference block and the current block. The coding apparatus may determine a mode that is applied to the current block from among several prediction modes. The coding apparatus can compare rate distortion (RD) costs for the various prediction modes, and determine an optimal prediction mode for the current block.

[0106] For example, in the case when a skip mode or merge mode is applied to the current block, the encoding apparatus configures a merge candidate list, and among the reference blocks that are indicated by the merge candidates included in the From the fusion candidate list, a reference block having a minimum difference from the current block or having a difference from the current block that is equal to or less than a predetermined reference standard can be derived. In this case, a fusion candidate that is associated with the derived reference block can be selected, and fusion index information indicating the selected fusion candidate can be generated and then signaled to the decoding apparatus. The motion information of the current block can be derived using motion information of the selected fusion candidate.

[0107] As another example, when an (A)MVP mode is applied to the current block, the encoding apparatus configures an (A)MVP candidate list, and a motion vector from a motion vector predictor candidate. Selected (mvp), which is selected from mvp candidates that are included in the (A)MVP candidate list, can be used as the mvp of the current block. In this case, for example, the motion vector indicating a reference block that is derived by the previously described motion estimation can be used as the motion vector of the current block, and, among the mvp candidates, an mvp candidate having a motion vector with the smallest difference from the current block's motion vector can be the selected mvp candidate. A motion vector difference (MVD), which is a difference obtained by subtracting the mvp from the motion vector of the current block, can be derived. In this case, MVD-related information can be signaled to the decoding apparatus. Additionally, when the (A)MVP mode is applied, a reference figure index value can be configured from reference figure index information, and can be separately signaled to the decoding apparatus.

[0108] The coding apparatus may derive residual samples based on the prediction samples (S610). The coding apparatus can derive the residual samples by comparing the prediction samples with original samples from the current block.

[0109] The coding apparatus encodes image information including prediction information and residual information (S620). The encoding apparatus may output the encoded image information in a bit stream format. The prediction information may be information related to the prediction procedure which may include prediction mode information (e.g., omission flag, fusion flag or mode index, and so on) and the information related to motion information. Information related to motion information may include candidate selection information (e.g., fusion index, mvp flag, or mvp index) which is information for deriving a motion vector. Additionally, information related to motion information may include the information described above regarding MVD information and/or reference figure index. Additionally, information related to motion information may include information indicating whether L0 prediction, L1 prediction or biprediction applies. Residual information is information related to residual samples. The residual information may include information related to the quantized transform coefficients for the residual samples.

[0110] The emitted bit stream may be stored on a (digital) storage medium and then delivered to the decoding apparatus, or the emitted bit stream may be delivered to the decoding apparatus via a network.

[0111] However, the coding apparatus described above can generate a reconstructed figure (including reconstructed samples and reconstructed block) based on the reference samples and the residual samples. This is done so that the coding device can derive a prediction result that is equal to the prediction result obtained by the prediction procedure performed on the decoding apparatus, and also because the coding efficiency can be enhanced accordingly. Therefore, the encoding apparatus can store a reconstructed figure (or reconstructed samples, reconstructed block) in a memory, and can use the stored figure as a reference figure for interprediction. As described previously, a loop filtering procedure, and so on, can be additionally applied to the reconstructed figure.

[0112] A video/image decoding procedure that relies on interprediction may generally include, for example, the following.

[0113] Figure 8 shows an example of an interprediction-based video/image decoding method, and Figure 9 shows an overview of an interpredictor in a decoding apparatus.

[0114] A decoding apparatus can perform operations that correspond to the operations performed by the encoding apparatus. The decoding apparatus may perform a prediction on a current block based on the received prediction information, and may derive prediction samples.

[0115] More specifically, referring to Figure 8 and Figure 9, the decoding apparatus may determine a prediction mode for the current block based on prediction information received from a bit stream (S800) . The decoding apparatus may determine which interprediction mode is applied to the current block based on the prediction mode information in the prediction information.

[0116] For example, one can determine, based on a fusion flag, whether or not a fusion mode is applied to the current block or whether or not an (A)MVP mode is determined. Alternatively, an interprediction mode candidate can be selected from multiple interprediction mode candidates based on the fusion index. Interprediction mode candidates may include various interprediction modes, such as an omission mode, a fusion mode, and/or an (A)MVP mode, and so on.

[0117] The decoding apparatus derives motion information from the current block based on the determined interprediction mode (S810). For example, when a skip mode or merge mode is applied to the current block, the decoding apparatus sets up a list of merge candidates, which will be described in detail later, and can select a merge candidate from the merge candidates. included in the list of merger candidates. Selection can be performed based on the fusion index described previously. The motion information of the current block can be derived using motion information of the selected fusion candidate. The motion information of the selected fusion candidate can be used as the motion information of the current block.

[0118] As another example, when an (A)MVP mode is applied to the current block, the decoding apparatus configures an (A)MVP candidate list, and a motion vector from a motion vector predictor candidate Selected (mvp), which is selected from mvp candidates that are included in the (A)MVP candidate list, can be used as the mvp of the current block. Selection can be performed based on the previously described selection information (mvp flag or mvp index). And in this case, an MVD of the current block can be derived based on the information in the MVD, and a motion vector of the current block can be derived based on the mvp of the current block and the MVD. Additionally, a reference figure index of the current block can be derived based on the reference figure index information. A figure that is indicated by the reference figure index in a reference figure list related to the current block can be derived as a reference figure being referred to for the interprediction of the current block.

[0119] However, the movement information of the current block can be derived without configuring any candidate list, in which case the previously described candidate list configuration can be omitted.

[0120] The decoding apparatus may generate prediction samples for the current block based on the movement information of the current block (S820). In this case, the decoding apparatus may derive the reference figure based on a reference figure index of the current block, and then the decoding apparatus may derive the prediction samples of the current block using samples from a block reference that is indicated by the motion vector of the current block in the reference figure. In this case, among the prediction samples of the current block, a prediction sample filtering procedure, which will be described later in greater detail, may additionally be performed on all, or part of, the prediction samples of the current block.

[0121] For example, the interpredictor 332 of the decoding apparatus may include a prediction mode determiner 332_1, a motion information derivator 332_2, and a prediction sample derivator 332_3. The prediction mode determiner 332_1 may determine a prediction mode for the current block based on the received prediction mode information, the motion information deriver 332_2 may derive the motion information (motion vector and/or figure index reference, and so on) of the current block based on the information in the received motion information, and the prediction sample derivative 332_3 can derive the prediction samples of the current block.

[0122] The decoding apparatus generates residual samples for the current block based on the received residual information (S830). The decoding apparatus can generate reconstructed samples for the current block based on the prediction samples and residual samples and generate a reconstructed figure based on the generated reconstructed samples (S840). Subsequently, as described previously, a loop filtering procedure, and so on, can be additionally applied to the reconstructed figure.

[0123] However, as previously described, a high-level syntax (HLS) can be encoded/signaled for video/image coding. A coded figure can be configured by one or more slices. A parameter that describes the encoded figure is flagged in a picture header, and a parameter that describes a slice is flagged in a slice header. The figure header is realized in its own NAL unit format. And, the slice header is present at a start (or starting point) of a NAL unit including a slice payload (i.e., slice data).

[0124] Each figure is associated with a figure header. A figure can be configured by different types of slices (an intracoded slice (i.e., I-slice) and intercoded slices (i.e., P-slice and B-slice)). Therefore, a figure header can include syntax elements that are required in an intraslice of a figure and an interslice of a figure.

[0125] A figure can be partitioned (or divided into) sub-figurations, tiles and/or slices. A sub-figure flag may be present in a sequenced parameter set (SPS). And, a tile and square slice flag can be present in a figure parameter set (PPS). A raster scan slice flag may be present in a slice header.

[0126] For example, in relation to partitioning a figure, the syntax elements shown below in Table 1 can be included in an SPS syntax. [Table 1]

[0127] The syntax elements shown below in Table 2 can be included in a PPS syntax. [Table 2]

[0128] In Table 2, num_slices_in_tile_minus1[i] + 1 indicates a number of slices in a current tile, when an ith slice includes a subset of CTU rows in a single tile. A value of num_slices_in_tile_minus1[i] must be within an inclusive range of 0 to RowHeight[tileY] - 1. In this document, tileY is an index of a tile row that includes an ith slice. When num_slices_in_tile_minus1[i] is not present in a PPS, the value of num_slices_in_tile_minus1[i] is derived as 0.

[0129] slice_height_in_ctu_minus1[i] + 1 indicates a height of an ith rectangular slice in CTU row units, when an ith slice includes a subset of CTU rows in a single tile. A value of slice_height_in_ctu_minus1[i] must be within an inclusive range of 0 to RowHeight[tileY] - 1. In this document, tileY is an index of a tile row that includes an ith slice.

[0130] The syntax elements shown below in Table 3 can be included in a slice header syntax. [Table 3]

[0131] Referring to Tables 1 to 3, in the current tile and slice design, a rectangular slice may include one or more tiles. Alternatively, a rectangular slice can include an integer (or complete number) of CTU rows on a single tile.

[0132] When a rectangular slice includes an integer (or complete number) of CTU rows in a single tile (this corresponds to a case where the tile is partitioned into two or more slices), in current signaling, the height of each slice is explicitly signaled. However, this type of signaling is not an ideal signaling method.

[0133] A layout of slices in a tile may include a case where the heights of the slices in the tile are uniform with the exception of the last slice and a case where the heights of the slices in the tile are not uniform. When the heights of the slices in the tile are uniform with the exception of the last slice, since the heights of all slices excluding the last slice in the tile are equal, only the height of one slice can be simply flagged without having to explicitly flag the height of each slice. When the heights of the slices in the tile are not uniform, the height of each slice in the tile needs to be flagged.

[0134] The following drawings are illustrated in order to describe the detailed examples of the present specification. The detailed terms of the apparatus (or device) or the detailed terms of the signals/information specified in the drawings are merely exemplary. And therefore, the technical characteristics of the present specification will not be limited only to the detailed terms used in the following drawings.

[0135] This specification provides the methods to be followed in order to solve the problems described above. Items from each method can be applied independently or can be applied in combination.

[0136] For example, when a tile includes two or more slices, a number of slice heights being explicitly signaled in the CTU rows may be signaled. This can be referred to as the num_exp_slice_in_tile syntax element. In this case, syntax elements (an array of slice_row_height_minus1) for indices starting from 0 to num_exp_slice_in_tile - 1 can be flagged. This can be signaled as ue(v) or u(v), and a number of bits that signal these syntax elements can vary according to a number of CTU rows in a tile. In this document, ue(v) represents a 0th-order Exponential Golomb syntax element, and u(v) indicates that v number of bits are used, where the value of v varies according to the value of other elements of syntax.

[0137] The height of each slice starting from a first slice to an nth slice in the tile is given as values of slice_row_height_minus1 + 1 starting from 0 to num_exp_slice_in_tile - 1, respectively. In this document, n is equal to a number of slices being explicitly signaled in the tile (num_exp_slice_in_tile).

[0138] Although the remaining CTU rows that are greater than num_exp_slice_in_tile_minus1 + 1 and (explicitly) flagged last in the tile are still present, a new slice is defined in the tile. In other words, slices that are not explicitly flagged are present on the tile. The last slice can have a height that is equal to or less than the num_exp_slice_in_tile_minus1 + 1 that was flagged last.

[0139] As another example, when a tile includes two or more slices, a number of slices being included in the tile may be signaled. In this case, a flag that indicates whether or not the heights of each slice in the tile are uniform can be flagged. When the heights of each slice in the tile are uniform, only one slice height can be signaled from the CTU rows. The height of each slice in the tile can be derived based on the flagged slice height. And, when the heights of each slice in the tile are not uniform, the heights of each slice excluding the last slice in the tile can be explicitly flagged.

[0140] In the present specification, information about slices and/or tiles may include information and/or syntax elements disclosed in Tables 1 to 3. Image/video information may include high-level syntax (HLS) disclosed in Tables 1 through 3, and the high-level syntax (HLS) may include slice-related information and/or tile-related information. Slice-related information may include information that indicates one or more slices in a current figure, and tile-related information may include information that indicates one or more tiles in the current figure. A tile including one or more slices and a slice including one or more tiles may be present in a figure.

[0141] As an embodiment, in order to represent a partitioned structure of a figure, syntaxes shown below in Table 4 and semantics shown below in Table 5 can be used for a PPS. [Table 4]

[0142] Referring to Tables 4 and 5, num_exp_slices_in_tile[i] + 1 represents a number of exp_slice_height_in_ctu_minus1[j] being present in a PPS. When num_exp_slices_in_tile[i] is not present in the PPS, a value of num_exp_slices_in_tile_minus1[i] is derived as 0.

[0143] exp_slice_height_in_ctu_minus1[j] + 1 indicates a height of a j-th rectangular slice being explicitly signaled in CTU row units, when an ith slice includes a subset of CTU rows in a single tile. A value of exp_slice_height_in_ctu_minus1[j] must be in an inclusive range of 0 to RowHeight[tileY] - 1. In this document, tileY is an index of a tile row including a slice.

[0144] That is, num_exp_slices_in_tile[i] can be referred to as information (numeric information) about a number of slices having their height explicitly signaled in the tile of a current figure. And, exp_slice_height_in_ctu_minus1[j] can be referred to as information (height information) about a height of each slice having its height explicitly signaled.

[0145] The numeric information and height information may be an Exponential Golomb-encoded syntax element.

[0146] Numerical information can be analyzed based on information about a width and height of a slice including the tile. When the tile includes an ith slice, the width information of the slice including the tile may correspond to the slice_width_in_tiles_minus1[i] syntax element, and the height information of the slice including the tile may correspond to the slice_height_in_tiles_minus1[i] syntax element. . The ith slice can be a rectangular slice, and slices in the tile can also be partitioned into rectangular slices.

[0147] For example, the encoding apparatus may generate numerical information and height information based on information about slices of the current figure. The numerical information and height information may be included in the image information and signaled to the decoding apparatus in a bitstream format.

[0148] When numerical information is analyzed from a PPS, as shown in Table 4, the decoding apparatus can analyze height information from the PPS based on the numerical information. For example, when a value of numerical information is equal to n (where n is an integer greater than or equal to 0), the decoding apparatus can analyze the height information in a number n of slices (starting from the 0th slice to (n-1)- th slice on the tile) from the PPS. The height information may indicate each of the height of the 0th slice to the height of the (n-1)th slice in coding tree unit (CTU) rows.

[0149] Thereafter, the decoding apparatus may derive the heights of the remaining slices in the tile based on the height of the (n-1)-th slice. More specifically, the decoding apparatus may derive the heights of the remaining slices by excluding the last slice in the tile starting from the nth slice in the tile as being equal to or greater than the (n-1)th slice. To do this, the decoding apparatus can compare a remaining height of the tile, which is calculated by subtracting a sum of the heights of the slices starting from the 0-th slice to the (n-1)-th slice from a total height of the tile in order to determine whether the remaining height is equal to or greater than a uniform slice height. In this document, a uniform slice can mean slices having a uniform height (the same height) on the tile. That is, the height of a uniform slice can be equal to the height of the (n-1)-th slice.

[0150] When the remaining tile height is equal to or greater than the height of a uniform slice, the height of the nth slice can be derived as the height of the uniform slice. And, when the remaining height of the tile is less than the height of a uniform slice, the height of the nth slice can be derived as the remaining height. Additionally, when the remaining tile height is equal to or greater than the height of a uniform slice, an updated remaining height can be derived by subtracting the height of the nth slice from the remaining height. And, when the updated remaining height is equal to or greater than the height of a uniform slice, the decoding apparatus may derive the height of an (n+1)-th slice as the height of a uniform slice. When the updated remaining height is less than the height of a uniform slice, the decoding apparatus may derive the height from the height of an (n+1)-th slice as the updated remaining height. That is, excluding the last slice in the tile, the height of the slices starting from the nth slice to the last slice can be derived as a uniform height. The height of the last slice can be equal to or less than the height of each uniform slice (slices starting from the (n-1)-th slice to a slice immediately before the last slice).

[0151] As an example, when 5 slices are included in a tile, and when the numerical information indicates 3, the height information for the first slice to the third slice in the tile can be analyzed from the PPS, and the height of the fourth slice in the tile can be derived to have the same height as the third slice. In this case, the height of the fifth slice may be greater or less than the height of the fourth slice.

[0152] The decoding apparatus may derive a number of slices in the tile by performing the scanning procedure described previously. When the value of numerical information is greater than 0, the procedure of deriving information about the height of each slice in the tile and information about a number of slices in the tile can be indicated as shown below in Table 5. [Table 6]

[0153] In the case of a rectangular slice, a list NumCtuInSlice[i] for i of an inclusive range from 0 to num_slices_in_pic_minus1 may indicate a number of CTUs in an ith slice, array CtbAddrInSlice[i][j] for i of an inclusive range from 0 to num_slices_in_pic_minus1 and j from an inclusive range from 0 to NumCtuInSlice[i] - 1 indicates a picture raster scan address of a j-th CTB in the ith slice and can be derived as shown below in Table 7. [Table 7] }

[0154] As another embodiment, in order to represent a partitioned structure of a figure, the syntaxes shown below in Table 8 and semantics shown below in Table 9 can be used for a PPS. [Table 8]

[0155] Referring to Tables 8 and 9, if a value of uniform_slice_spacing_flag[i] is equal to 1, this indicates that the CTU rows are uniformly distributed (or dispersed) throughout the entire tile and are flagged using- if syntax elements 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 uniformly distributed (or dispersed) across the entire tile and are signaled using syntax elements num_slices_in_tile_minus1[i ] and slice_height_in_ctu_minus1[i].

[0156] 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 slices excluding the last slice of the tile in CTB units. A value of slice_height_in_ctu_minus1[i] must be within an inclusive range of 0 to RowHeight[tileY] - 1. In this document, tileY is an index of a tile row including the slices.

[0157] num_slices_in_tile_minus1[i] + 1 indicates a number of slices in the current tile, when an ith slice includes a subset of CTU rows in a single tile, and when the value of uniform_slice_spacing_flag[i] is equal to 0. A value of num_slices_in_tile_minus1[i] must be within an inclusive range of 0 to RowHeight[tileY] - 1. In this document, tileY is an index of a tile row including an ith slice. When num_slices_in_tile_minus1[i] is not present, the value of num_slices_in_tile_minus1[i] is derived as 0.

[0158] slice_height_in_ctu_minus1[i] + 1 indicates a height of an ith rectangular slice in CTU row units, when an ith slice includes a subset of CTU rows in a single tile. A value of slice_height_in_ctu_minus1[i] must be within an inclusive range of 0 to RowHeight[tileY] - 1. In this document, tileY is an index of a tile row including an ith slice.

[0159] For example, the encoding apparatus may generate at least one of uniform_slice_spacing_flag, slice_rows_height_in_ctu_minus1, num_slices_in_tile_minus1 and slice_height_in_ctu_minus1 based on information about slices of the current figure.

[0160] When uniform_slice_spacing_flag is parsed from a PPS, as shown in Table 8, the decoding apparatus may parse slice_rows_height_in_ctu_minus1 or num_slices_in_tile_minus1 from the PPS based on a uniform_slice_spacing_flag value. For example, if the value of uniform_slice_spacing_flag is equal to 1, the decoder can parse slice_rows_height_in_ctu_minus1 from the PPS and can then derive the parsed result as the height of the remaining slices excluding the last slice in the tile based on the value of slice_rows_height_in_ctu_minus1. If the value of uniform_slice_spacing_flag is equal to 0, the decoder can parse num_slices_in_tile_minus1 and slice_height_in_ctu_minus1 from the PPS and can derive the slices in the tile based on the parsed result.

[0161] For example, the variables NumSlicesInTileMinus1[i] and SliceHeightInCtuMinus1[i+k] that are related to numerical information and height information of slices in a tile can be derived as shown below. In this document, k can be in an inclusive range from 0 to NumSlicesInTileMinus1[i]. Table 10]

[0162] In the case of a rectangular slice, a list NumCtuInSlice[i] for i of an inclusive range from 0 to num_slices_in_pic_minus1 may indicate a number of CTUs in an ith slice, array CtbAddrInSlice[i][j] for i of an inclusive range from 0 to num_slices_in_pic_minus1 and j from an inclusive range from 0 to NumCtuInSlice[i] - 1 indicates a picture raster scan address of a j-th CTB in the ith slice and can be derived as shown below in Table 11. Table 11]

[0163] Figures 10 and 11 respectively show general examples of a video/image coding method and a related component in accordance with an embodiment of the present disclosure.

[0164] The video/image coding method disclosed in Figure 10 can be performed by a (video/image) coding apparatus 200 which is disclosed in Figure 2 and Figure 11. More specifically, for example, S1000 10 may be realized by image partitioner 210 of coding apparatus 200, and S1010 may be realized by predictor 220 of coding apparatus 200. S1020 may be realized by residual processor 230 of coding apparatus 200. E, S1030 and S1040 may be performed by the entropy encoder 240 of the encoding apparatus 200. The video/image coding method disclosed in Figure 10 may include the embodiments that are described above in the present specification.

[0165] More specifically, referring to Figures 10 and 11, the image partitioner 210 of the encoding apparatus can derive slices in a tile from a current figure (S1000). For example, image partitioner 210 may partition an input image (or picture, frame) to one or more CUs. The input image may include one or more pictures. A figure can be partitioned into one or more tiles, bricks, slices and/or groups of tiles. A slice can include one or more bricks, tiles and/or groups of tiles. A brick may include one or more CTU rows. A tile group can include one or more tiles. A tile can include one or more CTUs. The CTU can be partitioned into one or more CUs. When a particular slice in the current figure is a rectangular slice, the image partitioner 210 may partition the rectangular slice into a plurality of tiles, and, among the plurality of tiles, the image partitioner 210 may partition at least one tile, and then , derive a plurality of rectangular slices.

[0166] The predictor 220 of the coding apparatus may perform a prediction on a current block based on the slices that are derived in the image partitioner 210 and may then generate prediction samples (prediction block) and information related to the prediction of the current block (S1010). The predictor 220 may determine whether an intraprediction is being applied, or whether an interprediction is being applied to the current block or CU units. The predictor 220 may deliver various prediction-related information (prediction-related information) to the entropy encoder 240. Herein, the prediction-related information may include information related to an interprediction mode and information related to an intraprediction mode. When the prediction mode of the current block is the interprediction mode, the prediction samples can be generated in the interpredictor 221 of the predictor 220. And, when the prediction mode of the current block is the intraprediction mode, the prediction samples can be generated in intrapredictor 222 of predictor 220.

[0167] The residual processor 230 of the coding apparatus may generate residual samples and residual information based on the prediction samples generated from the predictor 220 and an original figure (original block, original samples) (S1020). In this document, residual information is information related to residual samples, and residual information may include information related to transformed (quantized) coefficients for residual samples.

[0168] The adder (or reconstructor) of the coding apparatus can generate reconstructed samples (reconstructed figure, reconstructed block, reconstructed sample array) by adding residual samples that are generated in the residual processor 230 and the prediction samples that are generated in the interpredictor 221 or intrapredictor 222.

[0169] The entropy encoder 240 of the encoding apparatus may generate partitioning-related information based on a partitioning structure, which is derived in the image partitioner 210. The partitioning-related information may include information (numeric information) about a number of slices each having its height explicitly signaled in a tile and information (height information) about a height of the slices each having its height explicitly signaled. For example, the entropy encoder 240 may generate numerical information related to a number of slices each having their height explicitly signaled (provided) in the tile and height information related to a height of the slices each having their height explicitly signaled (provided) in the tile. flagged (provided) based on the slices that are derived in image partitioner 210 (S1030). In this document, numeric information may include the previously described syntax elements num_exp_slices_in_tile and/or num_slices_in_tile_minus1. Height information may include the previously described syntax elements exp_slice_height_in_ctu_minus1, slice_rows_height_in_ctu_minus1, and/or slice_height_in_ctu_minus1.

[0170] The entropy encoder 240 may encode image information including partitioning-related information, which includes numerical information and height information, prediction-related information, which is generated in the predictor 220, and/or residual information, which is generated on the residual processor 230 (S1040). The information that is encoded in the entropy encoder 240 may be output in a bitstream format. The bit stream can be transmitted to the decoding apparatus via a network or storage media.

[0171] For example, the entropy encoder 240 may include image information, which includes the syntax element num_exp_slices_in_tile as the numeric information and the syntax element exp_slice_height_in_ctu_minus1 as the height information based on Tables 4 and 5 described previously. The height information may indicate the height of slices each having its height explicitly signaled on the tile in the CTU row units, and to this end, the height information may include syntax elements for the slices each having its height explicitly signaled. The number of syntax elements being included in the image information can be equal to the value of numeric information.

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

[0173] The entropy encoder 240 may signal the numerical information and the height information through a set of figure parameters (PPS) in the image information. In this case, the entropy encoder 240 may include the numerical information and/or the height information using an Exponential Golomb method.

[0174] Figures 12 and 13 respectively show general examples of a video/image decoding method and a related component in accordance with an embodiment of the present disclosure.

[0175] The video/image decoding method disclosed in Figure 12 can be performed by a (video/image) decoding apparatus 300 which is disclosed in Figures 3 and 13. More specifically, for example, S1200 to S1220 of Figure 12 can be performed by the entropy decoder 310 of the decoding apparatus. S1230 of Figure 12 can be realized by the predictor 330 of the decoding apparatus. And, S1240 and S1250 of Figure 12 can be realized by the adder 340 of the decoding apparatus. The video/image decoding method disclosed in Figure 12 may include the embodiments that have been described above in the present specification.

[0176] Referring to Figures 12 and 13, the entropy decoder 310 of the decoding apparatus can obtain partitioning-related information, residual information, prediction-related information (inter/intra-prediction differentiation information, intra-prediction mode information, interprediction mode information, and so on), information related to loop filtering, and so on, from a bit stream. In this document, information related to partitioning may include information (numeric information) about a number of slices each having its height explicitly signaled, among the slices in a tile of a current figure, information (height information) about the height of slices each having its height explicitly signaled, and so on.

[0177] For example, the entropy decoder 310 may analyze information (numeric information) related to a number of slices each having its explicitly signaled height, among the slices in a tile of a current figure, from a stream of bits (S1200), and can analyze information (height information) related to the height of the slices, each having its height explicitly signaled from the bit stream based on numerical information (S1210). More specifically, the entropy decoder 310 can analyze numerical information and height information from a set of picture parameters (PPS) of the bit stream based on Table 4 described previously. In this document, numerical information can be analyzed based on information about a width and height of a slice including the tile. At this point, the slice including the tile and/or slices in the tile may be rectangular slices. Numeric information and height information can be Exponential Golomb encoded syntax elements. Height information may include syntax elements for each slice having its height explicitly signaled. The number of syntax elements can be equal to the value of numeric information.

[0178] For example, the entropy decoder 310 may parse slice_width_in_tiles_minus1 and slice_height_in_tiles_minus1 syntax elements from the figure parameter set (PPS) based on Table 4, and the entropy decoder 310 may parse a num_exp_slices_in_tile syntax element to from the figure parameter set (PPS) based on the values of the slice_width_in_tiles_minus1 and slice_height_in_tiles_minus1 syntax elements. And, the entropy decoder 310 may parse a number of exp_slice_height_in_ctu_minus1 that is equivalent to the value of the num_exp_slices_in_tile syntax element from the figure parameter set (PPS).

[0179] When the value of the numerical information is equal to n, the entropy decoder 310 can derive heights from a 0-th slice to an (n-1)-th slice in the tile based on the height information. And, the entropy decoder 310 can derive a height of an nth slice in the tile based on the height of the (n-1)th slice. That is, the height of the nth slice can be derived as being equal to the height of the (n-1)th slice. In this document, the nth slice may not be the last slice in the tile. In other words, the entropy decoder 310 can derive the heights of the remaining slices (slices that are not explicitly flagged) by deleting the last slice in the tile to have the same height as the (n-1)-th slice. Therefore, the heights of the slices starting from the nth slice to the last slice in the tile can be uniform with the exception of the last slice in the tile. The entropy decoder 310 may derive the height of the last slice in the tile based on a height remaining after subtracting the heights of other slices in the tile from the height of the tile. When the heights of all slices in the tile have been derived, the entropy decoder 310 can derive a number of slices in the tile (S1220). In this document, the number of slices in the tile may correspond to a number of slices starting from the 0th slice to the last slice in the tile.

[0180] The decoding apparatus 300 may decode the current figure based on the slices of the current figure being derived by carrying out the process described previously. More specifically, the residual processor 320 of the decoding apparatus may generate residual samples based on the residual information that is obtained from the entropy decoder 310. The predictor 330 of the decoding apparatus may perform interprediction and/or intraprediction on a block current that is included in the slices in the figure based on prediction-related information that is obtained from the entropy decoder 310 in order to generate prediction samples (S1230). The adder 340 of the decoding apparatus may generate reconstructed samples based on the prediction samples that are generated in the predictor 330 and the residual samples that are generated in the residual processor 320 (S1240). And, the adder 340 of the decoding apparatus may generate a reconstructed figure (reconstructed block) based on the reconstructed samples (S1250).

[0181] Subsequently, a loop filtering procedure, such as deblocking, SAO and/or ALF filtering procedures, can be applied to the reconstructed figure as necessary in order to improve the subjective/objective figure quality.

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

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

[0184] When the num_slices_in_tile_minus1 syntax element is parsed, the entropy decoder 310 may parse a number of the slice_height_in_ctu_minus1 syntax element corresponding to the value of the num_slices_in_tile_minus1 syntax element, and the values may each be derived as the heights of each slice on the tile, respectively.

[0185] Although the methods have been described based on a flowchart in which steps or blocks are listed in sequence in the previously described embodiments, the steps of the present document are not limited to a certain order or simultaneously to a step different from that previously described. Furthermore, those skilled in the art will understand that the steps in the flowcharts are not exclusive, and other steps may be included or one or more steps in the flowcharts may be excluded without affecting the scope of this document.

[0186] The aforementioned method according to the present document may be in the form of software, and the encoding apparatus and/or the decoding apparatus according to the present document may be included in the apparatus for carrying out image processing, for example, from a TV, a computer, a smartphone, a set-top box, a display device, or the like.

[0187] When the embodiments in the present document are implemented in software, the aforementioned method can be implemented as a module (process, function, and the like) to perform the aforementioned function. The module can be stored in a memory, and executed by a processor. Memory may be located inside or outside the processor, and may be coupled to the processor by several well-known means. The processor may include application-specific integrated circuits (ASICs), other chipsets, logic circuits and/or data processing devices. Memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage media, and/or other storage devices. That is, the modalities described in this document can be realized by being implemented in a processor, a microprocessor, a controller or a chip. For example, the functional units illustrated in each drawing may be realized by being implemented in the computer, processor, microprocessor, controller, or chip. In this case, information for implementation (e.g. information in instructions) or algorithm may be stored on a digital storage medium.

[0188] Furthermore, the decoding apparatus and the encoding apparatus to which the embodiments of the present document are applied may be included in a multimedia broadcast transceiver, a mobile communication terminal, a home cinema video device, a digital cinema video camera, a surveillance camera, a video communication device, a real-time communication device such as video communication, a mobile data broadcast device, a storage medium, a camcorder, a video-on-demand (VoD) service, an Over-the-top (OTT) video device, an Internet data broadcast service provider, a three-dimensional (3D) video device, a virtual reality (VR) device , an augmented reality (AR) device, a video telephony device, a transportation terminal (e.g., a vehicle terminal (including autonomous vehicle), aircraft terminal, ship terminal, or the like), and a device medical video, and the like, and can be used to process video signals or data signals. For example, the OTT video device may include a game console, a Blu-ray player, an Internet-connected TV, a home theater system, a smartphone, a tablet PC, a Digital Video Recorder (DVR) and similar.

[0189] Furthermore, the processing method to which the embodiments of the present document are applied can be produced in the form of a program executed by a computer, and can be stored on a computer-readable recording medium. Multimedia data having a data structure in accordance with this document may also be stored on computer-readable recording media. Computer-readable recording media includes all types of storage devices and distributed storage devices where computer-readable data is stored. Computer-readable recording media may include, for example, a Blu-ray Disc (BD), a Universal Serial Bus (USB), a ROM, a PROM, an EPROM, an EEPROM, a RAM, a CD-ROM, a magnetic tape, a flexible floppy disk, and an optical data storage device. Furthermore, computer-readable recording media includes media implemented in the form of a carrier wave (e.g., transmission over the Internet). Furthermore, the bit stream generated by the encoding method can be stored on computer-readable recording media or transmitted over wired/wireless communication networks.

[0190] Furthermore, embodiments of the present document may be embodied as a computer program product by a program code, and the program code may be executed on the computer in accordance with the embodiments of the present document. Program code can be stored on a computer-readable carrier.

[0191] Figure 14 represents an example of a content streaming system to which the embodiment of this document can be applied.

[0192] Referring to Figure 14, the content streaming system to which embodiments of the present document are applied may generally include an encoding server, a streaming server, a web server, a media storage, a device user interface and a multimedia input device.

[0193] The encoding server functions to compress content entered from multimedia input devices, such as a smartphone, camera, camcorder and the like, to digital data, generate a bit stream, and transmit it to the streaming server . As another example, in a case where the multimedia input device such as smartphone, camera, camcorder or the like directly generates a bit stream, the encoding server can be omitted.

[0194] The bitstream may be generated by a coding method or a bitstream generation method to which embodiments of the present document are applied. And the streaming server can temporarily store the bitstream in a process to transmit or receive the bitstream.

[0195] The streaming server transmits multimedia data to the user equipment based on a user request via the web server, which functions as an instrument that informs a user of which service exists. When the user requests a service he wants, the web server transfers the request to the streaming server, and the streaming server transmits multimedia data to the user. In this sense, the content streaming system may include a separate control server, in which case the control server functions to control commands/responses between respective equipment in the content streaming system.

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

[0197] For example, user equipment may include a mobile telephone, a smartphone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation device , a slate PC, a tablet PC, an ultrabook, a wearable device (e.g., a watch-type terminal (smart watch), a glasses-type terminal (smart glasses), a head-mounted display (HMD)), a digital TV , a desktop computer, digital signage or similar.

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

Claims (13)

1. Video decoding device CHARACTERIZED by the fact that it comprises: a memory; and at least one processor connected to the memory, the at least one processor configured to: analyze numeric information relating to a number of explicit slices, each having its height explicitly signaled within a tile of a current figure from a bit stream ; analyze height information related to explicit slice heights, each having its height explicitly signaled from the bitstream based on the numerical information; derive a number of slices within the tile based on numerical information and height information; generate prediction samples by performing prediction on a current block of the current figure based on one of the slices within the tile; generate reconstructed samples based on the prediction samples; and generating a reconstructed figure for the current figure based on the reconstructed samples, wherein a number of syntax elements in the height information is equal to the number of explicit slices specified by the numeric information, wherein based on the number of explicit slices being equal to n, heights of a 0th slice to an (n-1)th slice within the tile are derived based on the syntax elements in the height information, where a height of an nth slice within the tile is derived based on the height of the (n-1)-th slice, and where a height of a last slice within the tile is derived based on a height remaining after subtracting the heights of other slices within the tile from a height of the tile. 2. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that the number of slices within the tile is equal to a number of slices starting from the 0th slice to the last slice. 3. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that the height of the n-th slice is derived as being equal to the height of the (n-1)-th slice. 4. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that the heights of the slices starting from the nth slice to a slice immediately preceding the last slice within the tile are uniform. 5. Video decoding apparatus according to claim 4, CHARACTERIZED by the fact that the height of the last slice is less than or equal to the height of the (n-1)-th slice. 6. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that the at least one processor is configured to: compare a remaining tile height that is calculated by subtracting a sum of the heights of the slices starting from from the 0th slice to the (n-1)th slice from a total tile height in order to determine whether the remaining height is equal to or greater than a uniform slice height, where the height of a slice uniform is equal to the height of the (n-1)-th slice, where, based on the remaining height of the tile which is calculated by subtracting a sum of the heights of the slices starting from the 0-th slice to the (n-1 )-th slice from a total tile height being equal to or greater than the uniform slice height, the nth slice having the height of a uniform slice is derived, and wherein, based on the remaining tile height that is calculated by subtracting a sum of the slice heights starting from the 0-th slice to the (n-1)-th slice from a total tile height being less than the height of the uniform slice, the n-th slice having the remaining height is derived. 7. Video decoding apparatus according to claim 6, CHARACTERIZED by the fact that, based on the remaining height being equal to or greater than the height of the uniform slice, an updated remaining height is derived, wherein the updated remaining height is updated by subtracting the height of the n-th slice from the remaining height of the tile which is calculated by subtracting the sum of the heights of the slices starting from the 0-th slice to the (n-1)-th slice from of the total height of the tile, wherein, based on the updated remaining height being equal to or greater than the height of the uniform slice, an (n+1)-th slice having the height of the uniform slice is derived, and wherein, based on the updated remaining height being less than the height of the uniform slice, an (n+1)-th slice having the updated remaining height is derived. 8. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that the numerical information and the height information include an Exp-Golomb encoded syntax element. 9. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that the numerical information includes a num_exp_slices_in_tile syntax element, and wherein the height information includes an exp_slice_height_in_ctu_minus1 syntax element. 10. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that the slices within the tile are rectangular slices. 11. Video decoding apparatus according to claim 1, CHARACTERIZED by the fact that numerical information is analyzed based on information related to a width and height of a slice including the tile. 12. Video coding device CHARACTERIZED by the fact that it comprises: a memory; and at least one processor connected to the memory, the at least one processor configured to: derive slices within a tile of a current figure; generate prediction samples by performing prediction on a current block based on one of the derived slices; generate residual information based on the prediction samples and an original figure; generating numerical information related to a number of explicit slices, each having its height explicitly signaled within the tile, and height information related to heights of the explicit slices, each having its height explicitly signaled based on the derived slices; and encoding image information to generate a bit stream, wherein the image information includes the residual information, the numeric information and the height information, wherein a number of syntax elements in the height information is equal to the number of slices explicit values specified by numeric information, where, based on the number of explicit slices being equal to n, the syntax elements in the height information indicate heights from a 0-th slice to an (n-1)-th slice within the tile, wherein a height of an nth slice within the tile is represented based on the height of the (n-1)th slice, and wherein a height of a last slice within the tile is represented based on a height remaining after subtract the heights of other slices within the tile from a tile height. 13. Apparatus for transmitting data to a video, the apparatus CHARACTERIZED by the fact that it comprises: at least one processor configured to obtain a bit stream for the video, wherein the bit stream is generated based on the derivation of slices within of a tile of a current figure, generating prediction samples by performing the prediction on a current tile based on one of the derived slices, generating residual information based on the prediction samples, generating numerical information related to a number of explicit slices, each having its height explicitly signaled within the tile and height information relating to the heights of the explicit slices, each having its height explicitly signaled, and encoding image information including the residual information, the numerical information and the height information; and a transmitter configured to transmit the data comprising the bit stream, wherein a number of syntax elements in the height information is equal to the number of the explicit slices specified by the numerical information, wherein, based on the number of the explicit slices being equal to n, the syntax elements in the height information indicate heights from a 0th slice to an (n-1)th slice within the tile, where a height of an nth slice within the tile is represented based on height of the (n-1)-th slice, and where a height of a last slice within the tile is represented based on a height remaining after subtracting the heights of other slices within the tile from a height of the tile.