BR122023023080A2 - IMAGE/VIDEO CODING METHOD AND DEVICE - Google Patents

Abstract

This is a video decoding method performed by a video decoding device in accordance with this document which comprises the steps of: acquiring image information from a bit stream, wherein the image information includes a figure header associated with the current figure including a plurality of slices; analyzing, from the figure header, a first flag that indicates whether information necessary for an interprediction operation for a decoding process is present in the figure header; analyzing, from the figure header, a second flag that indicates whether information necessary for an intraprediction operation for the decoding process is present in the figure header; and generating prediction samples by performing at least one of intraprediction or interprediction for the slices in the current figure based on the first flag or the second flag.

Description

FUNDAMENTALS OF REVELATION Field of Revelation

[001] The present technology relates to a method and apparatus for encoding 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

[005] A technical subject of the present document is to provide a method and apparatus for enhancing the efficiency of image/video coding.

[006] Another technical subject of this document is to provide a method and apparatus for efficiently performing interprediction and/or intraprediction in image/video coding.

[007] Yet another technical subject of the present document is to provide a method and apparatus for omitting unnecessary signaling for interprediction and/or intraprediction in transferring image/video information.

[008] According to an embodiment of the present document, a video decoding method performed by a video decoding apparatus may include: obtaining image information from a bit stream, wherein the image information includes a header figure related to a current figure, wherein the current figure includes a plurality of slices; analyzing, from the figure header, a first flag representing whether information necessary for an interprediction operation for a decoding process is present in the figure header; analyzing, from the figure header, a second flag representing whether information necessary for an intraprediction operation for the decoding process is present in the figure header; and generating prediction samples by performing at least one of an intraprediction or an interprediction for the slices in the current figure based on the first flag and the second flag.

[009] According to another embodiment of the present document, a video coding method performed by a video coding apparatus may include: determining a prediction mode of a current block in a current figure, wherein the current figure includes a plurality of slices; generating first information representing whether information necessary for an interprediction operation for a decoding process is present in a figure header related to the current figure based on the prediction mode; generating second information representing whether information necessary for an intraprediction operation for the decoding process is present in the figure header based on the prediction mode; and encoding image information that includes the first information and the second information, wherein the first information and the second information are included in the figure header of the image information.

[010] According to yet another embodiment of the present document, a computer-readable digital storage medium including information that induces a decoding apparatus to perform a video decoding method, wherein the decoding method may include: obtaining information from image from a bit stream, wherein the image information includes a picture header relating to a current picture, wherein the current picture includes a plurality of slices; analyzing, from the figure header, a first flag representing whether information necessary for an interprediction operation for a decoding process is present in the figure header; analyzing, from the figure header, a second flag representing whether information necessary for an intraprediction operation for the decoding process is present in the figure header; and generating prediction samples by performing at least one of an intraprediction or an interprediction for the slices in the current figure based on the first flag and the second flag.

[011] According to one embodiment of the present document, the overall image/video compression efficiency can be enhanced.

[012] According to an embodiment of the present document, interprediction and/or intraprediction can be efficiently performed during image/video coding.

[013] According to an embodiment of the present document, signaling of a syntax element unnecessary for interprediction or intraprediction can be avoided during image/video transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

[014] Figure 1 shows, schematically, an example of a video/image coding system to which the modalities of the present disclosure can be applied.

[015] Figure 2 is a diagram that schematically illustrates a configuration of a video/image coding apparatus to which the modalities of the present disclosure can be applied.

[016] Figure 3 is a diagram that schematically illustrates a configuration of a video/image decoding apparatus to which the modalities of the present disclosure can be applied.

[017] Figure 4 shows an example of a video/image coding method based on intraprediction.

[018] Figure 5 shows an example of a video/image decoding method based on intraprediction.

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

[020] Figure 7 illustrates an example of an interprediction-based video/image decoding method.

[021] Figures 8 and 9 schematically illustrate a video/image coding method and an example of related components according to an embodiment of the present document.

[022] Figures 10 and 11 schematically illustrate a video/image decoding method and an example of related components according to an embodiment of the present document.

[023] Figure 12 illustrates an example of a content streaming system to which the modalities disclosed in this document are applicable.

DESCRIPTION OF EXEMPLIFYING MODALITIES

[024] The disclosure of the present disclosure may be modified in various ways and specific embodiments thereof will be described and illustrated in the drawings. Terms used in the present disclosure are used only to describe specific embodiments, but are not intended to limit the method disclosed in the present disclosure. 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.

[025] 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 disclosure, embodiments in which configurations are combined and/or separate are included within the scope of the disclosure of the present disclosure.

[026] Hereinafter, embodiments of the present disclosure 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.

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

[028] 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 transmission.

[029] 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.

[030] 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.

[031] 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.

[032] 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.

[033] 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.

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

[035] 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.).

[036] 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.

[037] 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 CTU in the tile. A tile that is not partitioned into multiple bricks 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 be made up 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 may be used interchangeably. For example, in this document, a tile group/tile group header may be referred to as a slice/slice header.

[038] 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.

[039] 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.

[040] 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”.

[041] 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 ”.

[042] 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”.

[043] In this specification, technical resources individually explained in a drawing can be individually implemented, or can be simultaneously implemented.

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

[045] 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.

[046] 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 the disclosure herein may be performed 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.

[047] 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).

[048] 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 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.

[049] 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.

[050] The interpredictor 221 may induce a block from the predicted current block based on a reference block (reference sample array) 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.

[051] 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.

[052] 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.

[053] 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.

[054] 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.

[055] 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.

[056] The quantized transform coefficients 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.

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

[058] 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.

[059] 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.

[060] 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.

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

[062] 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.

[063] 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.

[064] 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.

[065] The residual processor 320 can derive a residual signal (residual block, residual samples, and 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.

[066] 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.

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

[068] 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.

[069] 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.

[070] 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 can determine the prediction mode to be applied to the current block using the prediction mode applied to the neighboring block.

[071] 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.

[072] The adder 340 can generate a reconstructed signal (reconstructed figure, reconstructed block or reconstructed sample matrix) by summing the residual signal obtained 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.

[073] 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.

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

[075] 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.

[076] 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.

[077] 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.

[078] 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 ((inverse) transform and (de)quantization), syntax element coding and filtering to be described later can be performed based on CTU and CU (and/or TU and PU) derived 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 (encoded) 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 can derive the block partitioning structure of the current picture based on the partitioning-related information obtained from the bit stream, and based on this, can perform a series of image decoding procedures. (e.g., prediction, residual processing, block/figure reconstruction, and loop filtering). The CU size and the TU size may be equal to each other, or a plurality of TUs may be present in the CU area. 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 the 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, 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 the generation of a prediction sample 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) area, and in this case, the plurality of TUs (or TBs) may share the same intraprediction mode/type.

[079] Furthermore, in video/image coding according to this document, the image processing unit may have a hierarchical structure. A figure can be divided into one or more tiles, bricks, slices and/or groups of tiles. A slice can include one or more bricks. A brick may include one or more CTU rows in a tile. The slice can include an integer number of bricks in the figure. A tile group can include one or more tiles. A tile is a rectangular region of CTUs within a particular tile column and a particular tile row in a figure. The tile group can include an integer number of tiles according to the 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, the encoding/decoding procedures for the tile, slice, brick and/or group of tiles may be processed in parallel. In this document, the slice or group of tiles may be used interchangeably. That is, the tile group header can be termed as a slice header. Herein, the slice may have one of the types of slices including an intra (I) slice, a predictive (P) slice, and a bi-predictive (B) slice. For block prediction in slice I, interprediction may not be used, but only intraprediction may be used. Even in this case, the original sample value can be encoded and flagged without the prediction. For blocks in slice P, intraprediction or interprediction can be used, and in case of using interprediction, only uniprediction can be used. However, for blocks in slice B, intraprediction or interprediction can be used, and in case of using interprediction, maximally even biprediction can be used.

[080] According to the characteristics (e.g., resolution) of the video image, or in consideration of coding efficiency or parallel processing, the encoder may determine the tile/tile group, brick, slice, coding unit sizes maximum and minimum, and corresponding information or information capable of inducing the same may be included in the bit stream.

[081] The decoder may obtain information representing whether the brick/group of bricks, slice, or CTU in the tile of the current figure have been partitioned into a plurality of coding units. By obtaining (transmitting) this information only under a specific condition, efficiency can be enhanced.

[082] 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 can be additionally added for the plurality of slices (set of slice header and slice data) in a figure. The figure header (figure header syntax) may include information/parameters capable of being commonly applied to the figure. The slice header (slice header syntax) may include information/parameters capable of being commonly applied to the slice. An adaptation parameter set (APS) or a figure parameter set (PPS) may include information/parameters capable of being commonly applied to one or more figures. A sequence parameter set (SPS) may include information/parameters capable of being commonly applied to one or more sequences. A video parameter set (VPS) may include information/parameters capable of being commonly applied to multiple layers. A decoding parameter set (DPS) may include information/parameters capable of being commonly applied to the overall video. The DPS may include information/parameters related to the concatenation of a coded video sequence (CVS).

[083] In this document, a higher layer syntax may include at least one of APS syntax, PPS syntax, SPS syntax, VPS syntax, DPS syntax, figure header syntax and slice header syntax .

[084] Furthermore, for example, information about the division and configuration of the tile / group of tiles / brick / slice can be configured by the encoding end through the higher-level syntax, and can be transferred to the decoding apparatus in the form of a bit stream.

[085] 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.

[086] 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.

[087] According to the contents described above, the coding apparatus can perform various coding methods, such as, for example, exponential Golomb, context-adaptive variable-length coding (CAVLC), context-adaptive binary arithmetic coding (CABAC) and context-adaptive binary arithmetic (CABAC). Furthermore, the decoding apparatus may decode information in the bit stream based on the encoding method, such as exponential Golomb, CAVLC or CABAC, and may output a value of a syntax element and quantized values of transform-to-residual coefficients. necessary for image reconstruction. For example, the coding methods described above can be performed as per the contents that will be described later.

[088] In the present document, intraprediction may represent the prediction that generates the prediction samples for the current block based on the reference samples in the figure (hereinafter, current figure) to which the current block belongs. In the case where intraprediction is applied to the current block, neighboring reference samples to be used for intraprediction of the current block can be derived. The neighboring reference samples of the current block may include a sample adjacent to the left boundary of the current block having the size of nWxnH and 2xnH samples in total neighboring the lower left, a sample adjacent to the upper boundary of the current block and 2xnW samples in the total neighboring to the upper right, and a neighboring sample to the upper left of the current block. Furthermore, the neighboring reference samples of the current block may include a plurality of upper neighboring sample columns and a plurality of left neighboring sample rows. Furthermore, the neighboring reference samples of the current block may include a total of nH samples adjacent to the right boundary of the current block having the size of nWxnH, a total of nW samples adjacent to the lower boundary of the current block, and a sample neighboring the bottom right of the current block.

[089] However, some of the neighboring reference samples of the current block may not yet have been decoded or enabled. In this case, the decoding apparatus may configure neighboring reference samples to be used for substation prediction of enabled samples for an unenabled sample. Furthermore, neighboring reference samples to be used for prediction can be configured through interpolation of the enabled samples.

[090] In the case where neighboring reference samples are derived, (i) the prediction sample may be induced based on an average or interpolation of the neighboring reference samples of the current block, and (ii) the prediction sample may be induced based on the reference sample that is present in a specific direction (prediction) to the prediction sample among the neighboring reference samples of the current block. The case of (i) can be termed as a non-directional mode or a non-angular mode, and the case of (ii) can be termed as a directional mode or an angular mode. Furthermore, the prediction sample can be generated by interpolating the first neighboring sample with the second neighboring sample located in a direction opposite to the prediction direction of the current block intraprediction mode based on the prediction sample of the current block among the prediction samples. neighboring reference. The case described above can be termed as a linear interpolation intraprediction (LIP). Furthermore, chroma prediction samples can be generated based on luma samples using a linear model. This case can be termed as an LM mode. Furthermore, a temporary prediction sample of the current block can be derived based on the filtered neighboring reference samples, and a prediction sample of the current block can be derived by calculating a weighted sum of the temporary prediction sample and at least one sample of reference derived according to the intraprediction mode among the existing neighboring reference samples, i.e., unfiltered neighboring reference samples. The case described above can be termed as a position-dependent intraprediction (PDPC). Furthermore, the prediction sample may be derived using a reference sample lying in a prediction direction on a reference sample line having the highest prediction prediction among the neighboring multiple reference sample lines of the current block through the selection of the corresponding line, and in this case, intraprediction coding can be performed in a method for indicating (flagging) the reference sample line used to the decoding apparatus. The case described above can be referred to as multiple reference line interprediction (MRL) or MRL-based intraprediction. Furthermore, intraprediction can be performed based on the same intraprediction mode by dividing the current block into vertical or horizontal subpartitions, and neighboring reference samples can be derived and used in the unit of a subpartition. That is, in this case, since the intraprediction mode for the current block is equally applied to the subpartitions, and the neighboring reference samples are derived and used in the subpartition unit, the intraprediction performance may be enhanced in some cases. This partition method can be termed as intra-subpartitions (ISP) or ISP-based intraprediction. The previously described intraprediction method can be termed as intraprediction type in distinction from the intraprediction mode. The type of intraprediction can be called by various terms, such as an intraprediction technique or an additional intraprediction mode. For example, the intraprediction type (or additional intraprediction mode) may include at least one of the previously described LIP, PDPC, MRL, or ISP. A general intraprediction method excluding a specific intraprediction type, such as LIP, PDPC, MRL, or ISP, can be termed as a normal intraprediction type. The normal intraprediction type can be generically applied in the case where the specific intraprediction type is not applied, and the prediction can be performed based on the previously described intraprediction mode. However, as necessary, post-filtering can be performed for the derived prediction sample.

[091] Specifically, the intraprediction procedure may include the steps of determining intraprediction mode/type, deriving neighboring reference sample and deriving prediction sample based on intraprediction mode/type prediction sample. Furthermore, as necessary, a post-filtering step can be carried out for the derived prediction sample.

[092] However, in addition to the types of prediction described previously, an affine linear weighted intraprediction (ALWIP) can be used. ALWIP can be referred to as linear weighted intraprediction (LWIP) or matrix weighted intraprediction (MIP) or matrix-based intraprediction. In the case where MIP is applied to the current block, i) using the neighboring reference samples to which an averaging procedure was performed ii) a matrix vector multiplication procedure can be performed, and iii) as needed , the prediction samples for the current block can be derived by also performing a horizontal/vertical interpolation. The intraprediction modes being used for a MIP may be configured differently than the LIP, PDPC, MRL, or ISP intrapredictions described previously, or the intraprediction modes being used for a normal intraprediction. The intraprediction mode for MIP can be referred to as a MIP intraprediction mode, a MIP prediction mode, or a MIP mode. For example, depending on the intraprediction mode for MIP, a matrix and an offset being used for a matrix vector multiplication can be configured differently. In this document, the matrix may be referred to as a weighted matrix (MIP), and the deviation may be termed as a deviation vector (MIP) or a bias vector (MIP).

[093] Schematically, for example, the intraprediction-based video/image coding procedure may include the following.

[094] Figure 4 illustrates an example of a video/image coding method based on intraprediction.

[095] Referring to Figure 4, S400 can be performed by the intrapredictor 222 of the coding apparatus, and S410 to S430 can be realized by the residual processor 230 of the coding apparatus. Specifically, S410 can be realized by the subtractor 231 of the coding apparatus, S420 can be realized by the transformer 232 and the quantizer 233 of the coding apparatus, and S430 can be realized by the dequantizer 234 and the inverse transformer 235 of the coding apparatus. At S400, the prediction information can be derived by the intrapredictor 222, and can be encoded by the entropy encoder 240. Through S410 and S420, the residual information can be derived, and can be encoded by the entropy encoder 240. The residual information is information about the residual samples. The residual information may include information about the quantized transform coefficients for the residual samples. As described previously, the residual samples can be derived as transform coefficients through the transformer 232 of the coding apparatus, and the transform coefficients can be derived as the quantized transform coefficients through the quantizer 233. Information about the quantized transform coefficients can be encoded by the entropy encoder 240 through the residual encoding procedure.

[096] The coding device performs an intraprediction for the current block (S400). The coding apparatus may derive an intraprediction mode for the current block, derive neighboring reference samples from the current block, and generate prediction samples in the current block based on the intraprediction mode and neighboring reference samples. In this document, the procedures for determining the intraprediction mode, deriving the neighboring reference samples, and generating the prediction samples can be simultaneously performed, and any procedure can be performed before another procedure. For example, the intrapredictor 222 of the coding apparatus may include a prediction mode/type determinator, a reference sample derivator, and a prediction sample derivator, and the prediction mode/type determinator may determine the mode/type of intraprediction for the current block, the reference sample derivative can derive the neighboring reference samples from the current block, and the prediction sample derivative can derive motion samples from the current block. However, in the case where a prediction sample filtering procedure to be described later is performed, the intrapredictor 222 may further include a prediction sample filter. The coding apparatus may determine a mode being applied to the current block from among a plurality of intraprediction modes. The coding apparatus can compare RD costs for the intraprediction modes, and can determine the optimal intraprediction mode for the current block.

[097] However, the coding apparatus can perform the prediction sample filtering procedure. Prediction sample filtering can be termed as post-filtering. Some or all of the prediction samples may be filtered by the prediction sample filtering procedure. In some cases, the prediction sample filtering procedure may be omitted.

[098] The coding apparatus derives residual samples for the current block based on prediction samples (S410). The coding apparatus can compare the prediction samples with the original samples of the current block based on phase, and can derive the residual samples.

[099] The coding apparatus can derive quantized transform coefficients by transforming/quantizing the residual samples (S420), and then can derive the residual (modified) samples by performing dequantization / inverse transform of the quantized transform coefficients again (S430). The reason for performing the dequantization/inverse transform again after the transform/quantization is to derive the same residual samples as the residual samples being derived by the decoding apparatus as described previously.

[0100] The encoding apparatus may generate a reconstructed block including reconstructed samples for the current block based on the prediction samples and the residual (modified) samples (S440). Based on the reconstructed block, a reconstructed figure for the current figure can be generated.

[0101] As described previously, the encoding apparatus may encode image information including prediction information in the intraprediction (e.g., prediction mode information representing the prediction mode) and the residual information about intra/residual samples, and may output the encoded image information in the form of a bit stream. Residual information may include residual encoding syntax. The encoding apparatus may derive quantized transform coefficients by transforming/quantizing the residual samples. Residual information may include information about quantized transform coefficients.

[0102] For example, schematically, the intraprediction-based video/image decoding procedure may include the following.

[0103] Figure 5 illustrates an example of an intraprediction-based video/image decoding method.

[0104] The decoding apparatus can perform an operation corresponding to the operation performed by the encoding apparatus.

[0105] Referring to Figures 5, S500 to 510 can be performed by the intrapredictor 331 of the decoding apparatus, and the prediction information of S500 and residual information of S530 can be obtained from a bit stream by the entropy decoder 310 of the decoding device. The residual processor 320 of the decoding apparatus may derive residual samples for the current block based on the residual information. Specifically, the dequantizer 321 of the residual processor 320 may derive transform coefficients by performing dequantization based on the quantized transform coefficients derived based on the residual information, and the inverse transformer 322 of the residual processor may derive the residual samples for the block current by performing dequantization for the transform coefficients. S540 can be realized by adder 340 or by the decoding apparatus reconstructor.

[0106] Specifically, the decoding apparatus may derive the intraprediction mode for the current block based on the received prediction information (S500). The decoding apparatus may derive neighboring reference samples from the current block (S510). The decoding device generates prediction samples in the current block by performing intra-prediction based on the intra-prediction mode and neighboring reference samples (S520). In this case, the decoding apparatus can perform the prediction sample filtering procedure. Prediction sample filtering can be termed as post-filtering. Some or all of the prediction samples may be filtered by the prediction sample filtering procedure.

[0107] The decoding apparatus generates the residual samples for the current block based on the received residual information (S530). The decoding apparatus may generate reconstructed samples for the current block based on the prediction samples and the residual samples, and may derive a reconstructed block including the reconstructed samples (S540). A reconstructed figure for the current figure can be generated based on the reconstructed block.

[0108] Herein, the intrapredictor 331 of the decoding apparatus may include a prediction mode/type determiner, a reference sample derivative, and a prediction sample derivative. The prediction mode/type determiner may determine the intraprediction mode for the current block based on the prediction mode information obtained by the entropy decoder 310 of the decoding apparatus, the reference sample deriver may derive the neighboring reference samples from the current block, and the prediction sample derivative can derive the prediction sample from the current block. However, in the case where the previously described prediction sample filtering procedure is performed, the intrapredictor 331 may further include a prediction sample filter.

[0109] The prediction information may include intraprediction mode information and/or intraprediction type information. For example, the intraprediction mode information may include flag information (e.g., intra_luma_mpm_flag) that represents whether a most likely mode (MPM) or a remainder mode is applied to the current block, and in the case where the MPM is applied to the block current, the prediction mode information may further include index information (e.g., intra_luma_mpm_idx) that represents one of the intraprediction mode candidates (MPM candidates). Intraprediction mode candidates (MPM candidates) can constitute an MPM candidate list or an MPM list. Furthermore, in the case where MPM is not applied to the current block, the intraprediction mode information may also include remaining mode information (e.g., intra_luma_mpm_remainder) that indicates one of the remaining intraprediction modes excluding the intraprediction mode candidates. (MPM candidates). The decoding apparatus may determine the intraprediction mode of the current block based on the intraprediction mode information. For the MIP described previously, a separate MPM list can be configured.

[0110] Furthermore, intraprediction type information can be implemented in various forms. As an example, the intraprediction type information may include intraprediction type index information that indicates one of the intraprediction types. As another example, the intraprediction type information may include at least one of the reference sample line information (e.g., intra_luma_ref_idx) that represents whether the MRL is applied to the current block and which reference sample line is used in the case where MRL is applied, ISP flag information (e.g. intra_subpartitions_mode_flag) that represents whether ISP is applied to the current block, ISP type information (e.g. intra_subpartitions_split_flag) that indicates the type of subpartition partitioning in the case where ISP is applied, flag information that represents whether PDCP is applied, or flag information that represents whether LIP is applied. Furthermore, the intraprediction type information may include a MIP flag that represents whether MIP is applied to the current block.

[0111] Intraprediction mode information and/or intraprediction type information can be encoded/decoded via the encoding method described herein. For example, intraprediction mode information and/or intraprediction type information may be encoded/decoded via entropy coding (e.g., CABAC or CAVLC) based on truncated binary (rice) code.

[0112] However, schematically, for example, the interprediction-based video/image coding procedure may include the following.

[0113] Figure 6 illustrates an example of an interprediction-based video/image coding method.

[0114] Referring to Figure 6, the coding apparatus performs interprediction for the current block (S600). The coding apparatus can derive an interprediction mode and motion information from the current block, and can generate prediction samples from the current block. In this document, the procedures for determining the interprediction mode, deriving motion information, and generating the prediction samples may be performed simultaneously, and any procedure may be performed before another procedure. For example, the interpredictor of the coding apparatus may include a prediction mode determiner, a motion information derivative and a prediction sample derivative, and the prediction mode determinator may determine the prediction mode for the current block, the motion information derivative can derive the motion information of the current block and the prediction sample derivative can derive the prediction samples for the current block. For example, the interpredictor of the coding apparatus may search for a block similar to the current block in a specific area (search area) of the reference pictures through motion estimation, and may derive the reference block having a difference from the block current that is the minimum or equal to or less than a predetermined level. Based on this, a reference figure index indicating a reference figure where the reference block is situated is derived, and a motion vector is derived based on a difference in location between the reference block and the current block. The coding apparatus may determine a mode being 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 can determine the optimal prediction mode for the current block.

[0115] For example, in the case where a skip mode or a merge mode is applied to the current block, the encoding apparatus may configure a merge candidate list, and may derive the reference block having the difference from the current block that is the minimum or equal to or lower than the predetermined level among the reference blocks indicated by the merger candidates included in the merger candidate list. In this case, a fusion candidate related to the derived reference block may be selected, and fusion index information indicating the selected fusion candidate may be generated and signaled to the decoding apparatus. The motion information of the current block can be derived using the motion information of the selected fusion candidate.

[0116] As another example, in the case where an (A)MVP mode is applied to the current block, the encoding apparatus may configure an (A)MVP candidate list, and may use the motion vector of the MVP candidate selected from the motion vector predictor (mvp) candidates included in the (A)MVP candidate list as the mvp of the current block. In this case, for example, the motion vector indicating the reference block derived by the previously described motion estimation can be used as the motion vector of the current block, and the mvp candidate having the motion vector with the smallest difference to From the motion vector of the current block among the mvp candidates can be the selected mvp candidate. A motion vector difference (MVD), which is the difference obtained by subtracting the mvp from the motion vector of the current block, can be derived. In this case, information about the MVD can be signaled to the decoding apparatus. Furthermore, in the case where the (A)MVP mode is applied, the reference figure index value can be configured as the reference figure index information, and can be separately signaled to the decoding apparatus.

[0117] The coding apparatus may derive residual samples based on the prediction samples (S610). The encoding apparatus may derive the residual samples by comparing the prediction samples with the original samples of the current block.

[0118] The coding apparatus encodes image information including prediction information and residual information (S620). The encoding apparatus may output the encoded image information in the form of a bit stream. The prediction information may be information related to the prediction procedure, and may include information related to the prediction mode information (e.g., omission flag, fusion flag, or mode index) and the movement information. Information about the motion information may include candidate selection information (e.g., fusion index, mvp flag, or mvp index) which is the information for deriving the motion vector. Furthermore, the information about the motion information may include information about the MVD and/or reference figure index information described above. Furthermore, information about motion information may include information representing whether L0 prediction, L1 prediction or biprediction applies. Residual information is information about the residual samples. The residual information may include information about quantized transform coefficients for the residual samples.

[0119] The output bit stream may be stored on a (digital) storage medium to be transferred to the decoding apparatus, or may be transferred to the decoding apparatus via a network.

[0120] However, as described previously, the coding apparatus can generate a reconstructed figure (including reconstructed samples and reconstructed block) based on the reference samples and the residual samples. This serves for the coding device to derive the same prediction result as that performed in the decoding device, and through this, the coding efficiency can be enhanced. Correspondingly, the coding apparatus may store the reconstructed figure (or reconstructed samples or reconstructed block) in a memory, and may use the same as a reference figure for interprediction. As described previously, a lasso filtering procedure can be additionally applied to the reconstructed figure.

[0121] Schematically, for example, an interprediction-based video/image decoding procedure may include the following.

[0122] Figure 7 illustrates an example of an interprediction-based video/image decoding method.

[0123] The decoding apparatus can perform an operation corresponding to the operation performed by the encoding apparatus. The decoding apparatus may perform a prediction for the current block based on the received prediction information, and may derive prediction samples.

[0124] Specifically, referring to Figure 7, the decoding apparatus may determine a prediction mode for the current block based on prediction information received from a bit stream (S700). The decoding apparatus may determine which interprediction mode is applied to the current block based on the prediction mode information in the prediction information.

[0125] For example, it can be determined whether a merge mode is applied to the current block based on a merge flag, or an (A)MVP mode is determined. Furthermore, one of several interprediction mode candidates can be selected based on the fusion index. Interprediction mode candidates may include multiple interprediction modes, such as an omission mode, a fusion mode, and/or an (A)MVP mode.

[0126] The decoding apparatus derives motion information from the current block based on the determined interprediction mode (S710). For example, in the case where a skip mode or a merge mode is applied to the current block, the decoding apparatus may configure a list of merge candidates that will be described later, and may select one of the merge candidates included in the list of merges. merger candidates. Selection can be carried out based on the previously described selection information (fusion index). The motion information of the current block can be derived using the 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.

[0127] As another example, in the case where the (A)MVP mode is applied to the current block, the decoding apparatus may configure the (A)MVP candidate list, and may use the motion vector of the MVP candidate selected from the motion vector predictor (mvp) candidates included in the (A)MVP candidate list. Selection can be performed based on the previously described selection information (mvp flag or mvp index). In this case, the MVD of the current block can be derived based on the information in the MVD, and the motion vector of the current block can be derived based on the mvp and MVD of the current block. Furthermore, the reference figure index of the current block can be derived based on the reference figure index information. The figure indicated by the reference figure index in the reference figure list for the current block can be derived as the reference figure being referred to for the interprediction of the current block.

[0128] However, the movement information of the current block may be derived without the candidate list configuration, in which case the previously described candidate list configuration may be omitted.

[0129] The decoding apparatus may generate prediction samples for the current block based on the movement information of the current block (S720). In this case, the reference figure can be derived based on the reference figure index of the current block, and the motion vector of the current block can be derived from the prediction samples of the current block using samples from the reference block indicated in the figure of reference. In this case, as described later, the prediction sample filtering procedure can be additionally performed for all or some of the prediction samples in the current block as needed.

[0130] For example, the interpredictor of the decoding apparatus may include a prediction mode determiner, a motion information derivative, and a prediction sample derivative, and the prediction mode determiner may determine the prediction mode for the current block based on the received prediction mode information, the motion information derivative can derive the motion information (motion vector and/or reference figure index) of the current block based on the information in the received motion information, and the prediction sample derivative can derive the prediction samples from the current block.

[0131] The decoding apparatus generates residual samples for the current block based on the received residual information (S730). The decoding apparatus may generate reconstructed samples for the current block based on the prediction samples and residual samples (S740). Afterwards, the lasso filtering procedure can be additionally applied to the reconstructed figure as described previously.

[0132] However, as previously described, a high-level syntax (HLS) can be encoded/signaled for video/image coding. The coded figure can be composed of one or more slices. A parameter that describes the encoded figure is flagged in the figure header, and a parameter that describes the slice is flagged in the slice header. The figure header is realized in the form of an NAL unit itself. The slice header is present in an initial portion of the NAL unit including a slice payload (i.e., slice data).

[0133] Each figure is related to a figure header. The figure can be composed of different types of slices (intracoded slice (i.e., I-slice) and intercoded slice (i.e., P-slice and B-slice)). Correspondingly, the figure header may include syntax elements necessary for the figure intraslice and the ad figure interslice. For example, the figure header syntax may be as shown in Table 1 below. [Table 1]

[0134] Among the syntax elements of Table 1, syntax elements including “intra_slice” in their titles (e.g., pic_log2_diff_min_qt_min_cb_intra_slice_luma) are syntax elements being used in slice I of the corresponding figure, and syntax elements (e.g., pic_temporal_mvp_enabled_flag ) related syntax elements including “inter_slice” in their titles (e.g., pic_log2_diff_min_qt_min_cb_inter_slice, mvp, mvd, mmvd, and merge) are syntax elements being used in the P slice and/or B slice of the corresponding figure.

[0135] That is, the figure header includes all syntax elements required for the intracoded slice and syntax elements required for the intercoded slice for each single figure. However, this is only useful in relation to the figure including mixed type slices (figure including all of the intracoded slice and the intercoded slice). In general, since the figure does not include mixed-type slices (i.e., the overall figure includes only intracoded slices or only intercoded slices), it is unnecessary to perform a signaling of all data (syntax elements being used in the intracoded slice). and syntax elements being used in the intercoded slice).

[0136] The following drawings have been prepared to explain a detailed example of the present document. Since the name of a detailed device or the name of detailed signals/information are exemplarily presented, the technical features of this document are not limited to the detailed names used in the following drawings.

[0137] This document provides the methods to be followed in order to solve the problem described above. Items from each method can be applied individually, or they can be applied in combination.

[0138] 1. A flag in the figure header to specify whether syntax elements that are required only by intracoded slices are present in the figure header can be flagged. The flag can be referred to as intra_signaling_present_flag.

[0139] a) When intra_signaling_present_flag is equal to 1, syntax elements that are required by intracoded slices are present in the figure header. Similarly, when intra_signaling_present_flag is equal to 0, syntax elements that are required by intracoded slices are not present in the figure header.

[0140] b) The value of intra_signaling_present_flag in a figure header must be equal to 1 in the figure associated with the figure header having at least one intracoded slice.

[0141] c) The value of intra_signaling_present_flag in a figure header may be equal to 1 even when the figure associated with the figure header does not have an intracoded slice.

[0142] d) When a figure has one or more subfigurations containing intracoded slices only and it is anticipated that one or more of the subfigurations may be extracted and joined to subfigurations containing one or more intercoded slices, the value of intra_signaling_present_flag should be set equal to 1.

[0143] 2. A flag in the figure header to specify whether syntax elements that are required only by intercoded slices are present in the figure header can be flagged. The flag can be referred to as inter_signaling_present_flag.

[0144] a) When inter_signaling_present_flag is equal to 1, syntax elements that are required by intercoded slices are present in the figure header. Similarly, when inter_signaling_present_flag is equal to 0, syntax elements that are required by intercoded slices are not present in the figure header.

[0145] b) The value of inter_signaling_present_flag in a figure header must be equal to 1 in the figure associated with the figure header having at least one intercoded slice.

[0146] c) The value of inter_signaling_present_flag in a figure header may be equal to 1 even when the figure associated with the figure header does not have an intercoded slice.

[0147] d) When a figure has one or more subfigurations containing intercoded slices only and it is anticipated that one or more of the subfigurations may be extracted and joined to subfigurations containing one or more intracoded slices, the value of inter_signaling_present_flag should be set equal to 1.

[0148] 3. The previous flags (intra_signaling_present_flag and inter_signaling_present_flag) can be signaled in another parameter set such as a figure parameter set (PPS) instead of in the figure header).

[0149] 4. Another alternative to flagging the previous flags may be as follows.

[0150] a) Two variables IntraSignalingPresentFlag and InterSignalingPresentFlag that specify whether syntax elements required by intracoded slices and syntax element required by intercoded slices, respectively, present in the figure header can or cannot be defined.

[0151] b) A flag called mixed_slice_types_present_flag in the figure header may be flagged. When mixed_slice_types_present_flag is equal to 1, the values of IntraSignalingPresentFlag and InterSignalingPresentFlag are set to be equal to 1.

[0152] c) When mixed_slice_types_present_flag is equal to 0, an additional flag called intra_slice_only_flag may be flagged in the figure header and the following applies. If intra_slice_only_flag is equal to 1, the value of IntraSignalingPresentFlag is set to equal 1 and the value of InterSignalingPresentFlag is set to equal to 0. Otherwise, the value of IntraSignalingPresentFlag is set to equal to 0 and the value of InterSignalingPresentFlag is set to equal to 1.

[0153] 5. A fixed-length syntax element in the figure header, which may be named slice_types_idc, that specifies the following information may be flagged.

[0154] a) If the figure associated with the figure header contains intracoded slices only. For this type, the value of slice_types_idc can be set equal to 0.

[0155] b) If the figure associated with the figure header contains intercoded slices only, the value of slice_types_idc may be set equal to 1.

[0156] c) If the figure associated with the figure header can contain intracoded slices and intercoded slices, the value of slice_types_idc can be set equal to 2.

[0157] Note that when slice_types_idc has a value of 2, it is still possible for the figure to contain intracoded slices only or intercoded slices only.

[0158] d) Other slice_types_idc values may be reserved for future use.

[0159] 6. For semantics of slice_types_idc in a figure header, the following constraints may be additionally specified.

[0160] a) When the figure associated with the figure header has one or more intracoded slices, the value of slice_types_idc must not be equal to 1.

[0161] b) When the figure associated with the figure header has one or more intercoded slices, the slice_types_idc value must not be equal to 0.

[0162] 7. slice_types_idc may be flagged in another parameter set such as a figure parameter set (PPS) rather than in the figure header.

[0163] As one embodiment, the encoding apparatus and the decoding apparatus may use the following Table 2 and Table 3 as figure header syntax and semantics based on the methods of 1 and 2 as previously described. [Table 2] [Table 3] intra_signaling_present_flag equal to 1 specifies that syntax elements used only by intracoded slices are present in the figure header, intra_signaling_present_flag equal to 0 specifies that syntax elements used only by intracoded slices are not present in the figure header It is a requirement of bitstream compliance that the value of intra_signaling_present_flag must be equal to 1 when the figure associated with the figure header has one or more slices with slice_type

[0164] Referring to Table 2 and Table 3, if the value of intra_signaling_present_flag is 1, this may represent that the syntax element being used only in the intracoded slice is present in the figure header. If the value of intra_signaling_present_flag is 0, this may represent that the syntax element being used only in the intracoded slice is not present in the figure header. Correspondingly, if the figure related to the figure header includes one or more slices having the slice slice type I, the value of intra_signaling_present_flag becomes 1. Furthermore, if the figure related to the figure header does not include the slices having the slice slice type I, the value of intra_signaling_present_flag becomes 0.

[0165] If the value of inter_signaling_present_flag is 1, this may represent that the syntax element being used only in the intercoded slice is present in the figure header. If the value of inter_signaling_present_flag is 0, this may represent that the syntax element being used only in the intercoded slice is not present in the figure header. Correspondingly, if the figure related to the figure header includes one or more slices having the slice type of slice P and/or slice B, the value of intra_signaling_present_flag becomes 1. Furthermore, if the figure related to the figure header does not include slices having the slice type of slice P and/or slice B, the value of intra_signaling_present_flag becomes 0.

[0166] Furthermore, in case the figure includes one or more subfigurations including the intracoded slices that can be joined to one or more subfigurations including the intercoded slices, both the value of intra_signaling_present_flag and the value of inter_signaling_present_flag are set to 1.

[0167] For example, in the case where only the intercoded slices (slice P and/or slice B) are included in the current figure, the coding apparatus may determine the value of inter_signaling_present_flag as 1, and the value of intra_signaling_present_flag as 0.

[0168] As another example, in the case where only the intracoded slice (slice I) is included in the current figure, the coding apparatus may determine the value of inter_signaling_present_flag as 0, and the value of intra_signaling_present_flag as 1.

[0169] As yet another example, in the case where at least one intercoded slice or at least one intracoded slice is included in the current figure, the coding apparatus may determine the value of inter_signaling_present_flag and the value of intra_signaling_present_flag as 1 in all.

[0170] In the case where the value of intra_signaling_present_flag is determined to be 0, the encoding apparatus may generate image information where the syntax elements necessary for the intraslice are excluded or omitted, and only the syntax elements necessary for the interslice are included in the figure header. If the value of inter_signaling_present_flag is set to 0, the encoding apparatus can generate image information in which the syntax elements required for the interslice are deleted or omitted, and only the syntax elements required for the intraslice are included in the header. figure.

[0171] If the value of inter_signaling_present_flag obtained from the figure header in the picture information is 1, the decoding apparatus may determine that at least one intercoded slice is included in the corresponding figure, and may parse the syntax elements necessary for the intraprediction from the figure header. If the value of inter_signaling_present_flag is 0, the decoding apparatus may determine that only the intracoded slice is included in the corresponding figure, and may parse the syntax elements necessary for intraprediction from the figure header. If the value of intra_signaling_present_flag obtained from the figure header in the picture information is 1, the decoding apparatus may determine that at least one intracoded slice is included in the corresponding figure, and may parse the syntax elements necessary for intraprediction from of the figure header. If the value of intra_signaling_present_flag is 0, the decoding apparatus can determine that only the intercoded slice is included in the corresponding figure, and can parse the syntax elements necessary for interprediction from the figure header.

[0172] As another embodiment, the encoding apparatus and the decoding apparatus may use Table 4 and Table 5 below as the syntax and semantics of the figure header based on the previous methods of 5 and 6. [Table 4]

[0173] Referring to Table 4 and Table 5, if the value of slice_types_idc is 0, it represents that the type of all slices in the figure related to the figure header is slice I. If the value of slice_types_idc is 1, this represents that the type of all slices in the figure related to the figure header is slice P or B. If the value of slice_types_idc is 2, it represents that the slice type of the slices in the figure related to the figure header is slice I, P and/or B.

[0174] For example, if only the intra-coded slice is included in the current figure, the encoding apparatus may determine the value of slice_types_idc as 0, and may include only the syntax elements necessary for decoding the intra-slice in the figure header. That is, in this case, the syntax elements required for interslicing are not included in the figure header.

[0175] As another example, if only the intercoded slice is included in the current figure, the encoding apparatus may determine the value of slice_types_idc as 1, and may include only the syntax elements necessary for decoding the interslice in the figure header. That is, in this case, the syntax elements required for the intraslice are not included in the figure header.

[0176] As yet another example, if at least one intercoded slice and at least one intracoded slice are included in the current figure, the encoding apparatus may determine the value of slice_types_idc to be 2, and may include all syntax elements necessary for the interslice decoding and the syntax elements required for intraslice decoding in the figure header.

[0177] If the value of slice_types_idc obtained from the figure header in the image information is 0, the decoding apparatus may determine that only the intracoded slice is included in the corresponding figure, and may parse the syntax elements necessary for decoding of the intracoded slice from the figure header. If the value of slice_types_idc is 1, the decoding apparatus can determine that only the intercoded slice is included in the corresponding figure, and can parse the syntax elements necessary for decoding the intercoded slice from the figure header. If the value of slice_types_idc is 2, the decoding apparatus may determine that at least one intracoded slice and at least one intercoded slice are included in the corresponding figure, and may parse the syntax elements necessary for decoding the intracoded slice and the elements of syntax required for decoding the intercoded slice from the figure header.

[0178] As yet another embodiment, the encoding apparatus and the decoding apparatus may use a flag that represents whether the figure includes intra- and inter-coded slices. If the flag is true, that is, if the flag value is 1, all of the intra-slice and inter-slice can be included in the corresponding figure. In this case, Table 6 and Table 7 below can be used as the syntax and semantics of the figure header. [Table 6] [Table 7] mixed_slice_signaling_present_flag equal to 1 specifies that the figure associated with the figure header can have one or more slices with different types, mixed_slice_signaling_present_flag equal to 0 specifies that the figure associated with the figure header contains data belonging to only a single slice type . The variables InterSignalingPresentFlag and IntraSignalingPresentFlag are defined to specify whether syntax elements required by intracoded slices and syntax elements required by intercoded slices, respectively, are present in the figure or not. When mixed slice signaling present flag is equal to 1, InterSignalingPresentFlag and IntraSignalingPresentFlag are set to be equal to 1. intra_slice_only_flag equal to 1 specifies that the value of IntraSignalingPresentFlag is set to be equal to 1 and the value of InterSignalingPresentFlag is set to be equal to 0. intra_slice_only_flag equals 0 specifies that IntraSignalingPresentFlag is set equal to 0 and the value of InterSignalingPresentFlag is set equal to 1. It is a requirement of bitstream compliance that the value of IntraSignalingPresentFlag must be equal to 1 when the picture associated with the picture header has one or more with slice_type equal to I It is a bitstream compliance requirement that the value of InterSignalingPresentFlag must equal 1 when the picture associated with the picture header has one or more with slice_type equal to P or B. NOTE -: The values of intra_signaling_present_flag and inter_signaling_present_flag must be set equal to 1 in the figure header associated with the figure containing one or more subfigures containing intracoded slices that can be joined to one or more subfigures containing intercoded slices

[0179] Referring to Table 6 and Table 7, if the value of mixed_slice_signaling_present_flag is 1, it may represent that the figure related to the corresponding figure header has one or more slices having different types. If the value of mixed_slice_signaling_present_flag is 0, it could mean that the figure related to the corresponding figure header includes data related to only a single slice type.

[0180] The variables InterSignalingPresentFlag and IntraSignalingPresentFlag represent whether the syntax element required for the intracoded slice and the syntax element required for the intercoded slice are present in the corresponding figure header, respectively. If the value of mixed_slice_signaling_present_flag is 1, the values of IntraSignalingPresentFlag and InterSignalingPresentFlag are set to 1.

[0181] If the value of intra_slice_only_flag is set to 1, this represents that the value of IntraSignalingPresentFlag is set to 1, and the value of InterSignalingPresentFlag is set to 0. If the value of intra_slice_only_flag is 0, this represents that the value of IntraSignalingPresentFlag is set to 0, and the value of InterSignalingPresentFlag is set to 1.

[0182] If the figure related to the figure header has one or more slices having slice slice type I, the value of IntraSignalingPresentFlag is set to 1. If the figure related to the figure header has one or more slices having the type of P or B slice slice, the value of InterSignalingPresentFlag is set to 1.

[0183] For example, if only the intracoded slice is included in the current figure, the encoding apparatus may determine the value of mixed_slice_signaling_present_flag as 0, may determine the value of intra_slice_only_flag as 1, may determine the value of IntraSignalingPresentFlag as 1, and may set the value of InterSignalingPresentFlag to 0.

[0184] As another example, if only the intercoded slice is included in the current figure, the encoding apparatus may determine the value of mixed_slice_signaling_present_flag as 0, may determine the value of intra_slice_only_flag as 0, may determine the value of IntraSignalingPresentFlag as 0, and can set the value of InterSignalingPresentFlag to 1.

[0185] As yet another example, if at least one intracoded slice and at least one intercoded slice are included in the current figure, the encoding apparatus may determine the values of mixed_slice_signaling_present_flag, IntraSignalingPresentFlag, and InterSignalingPresentFlag as 1, respectively.

[0186] If the value of mixed_slice_signaling_present_flag obtained from the figure header in the picture information is 0, the decoding apparatus may determine that only the intracoded slice or the intercoded slice is included in the corresponding figure. In this case, if the value of intra_slice_only_flag obtained from the figure header is 0, the decoding apparatus can parse only those syntax elements necessary for decoding the intercoded slice from the figure header. If the value of intra_slice_only_flag is 1, the decoder can parse only the syntax element necessary for decoding the intracoded slice from the figure header.

[0187] If the value of mixed_slice_signaling_present_flag obtained from the picture header in the picture information is 1, the decoding apparatus can determine that at least one intracoded slice and at least one intercoded slice are included in the corresponding picture, and can analyze the syntax elements necessary for decoding the intercoded slice and the syntax elements necessary for decoding the intracoded slice from the figure header.

[0188] Figures 8 and 9 schematically illustrate a video/image coding method and an example of related components according to an embodiment of the present document.

[0189] The video/image coding method disclosed in Figure 8 can be performed by the (video/image) coding apparatus 200 disclosed in Figures 2 and 9. Specifically, for example, S800 of Figure 8 can be realized by the predictor 220 of the coding apparatus 200, and S810 to S830 may be performed by the entropy encoder 240 of the coding apparatus 200. The video/image coding method disclosed in Figure 8 may include the embodiments described earlier herein.

[0190] Specifically, with reference to Figures 8 and 9, the predictor 220 of the coding apparatus can determine the prediction mode of the current block in the current figure (S800). The current figure may include a plurality of slices. The predictor 220 of the coding apparatus may generate prediction samples (predicted block) for the current block based on the prediction mode. In this document, the prediction mode may include an interprediction mode and an intraprediction mode. If the prediction mode of the current block is the interprediction mode, the prediction samples may be generated by the interpredictor 221 of the predictor 220. If the prediction mode of the current block is the intraprediction mode, the prediction samples may be generated by the intrapredictor 222 of predictor 220.

[0191] The residual processor 230 of the coding apparatus can generate residual samples and residual information based on the prediction samples and the original figure (original block and original samples). In this document, residual information is information about the residual samples, and may include information about transformed (quantized) coefficients for the residual samples.

[0192] The adder (or reconstructor) of the coding apparatus may generate reconstructed samples (reconstructed figure, reconstructed block or array of reconstructed samples) by adding the residual samples generated by the residual processor 230 and the prediction samples generated by the interpredictor 221 or by the intrapredictor 222 among themselves.

[0193] However, the entropy encoder 240 of the encoding apparatus may generate first information that represents whether information necessary for the interprediction operation for the decoding process is present in the figure header related to the current figure (S810). Furthermore, the entropy encoder 240 of the encoding apparatus may generate second information that represents whether information necessary for the intraprediction operation for the decoding process is present in the figure header related to the current figure (S820). In this document, the first information and the second information are information included in the figure header of the image information, which may correspond to intra_signaling_present_flag, inter_signaling_present_flag, slice_type_idc, mixed_slice_signaling_present_flag, intra_slice_only_flag, IntraSignalingPresentFlag and/or InterSignalingPresentFlag described previously.

[0194] As an example, in the case where the information necessary for the interprediction operation for the decoding process is included in the figure header related to the current figure as the intercoded slice is included in the current figure, the entropy encoder 240 of the apparatus encoding may determine the value of the first information as 1. Furthermore, in the case where the information required for the intraprediction operation for the decoding process is included in the corresponding figure header as the intracoded slice is included in the current figure, the encoder entropy 240 of the coding apparatus may determine the value of the second information as 1. In this case, the first information may correspond to inter_signaling_present_flag, and the second information may correspond to intra_signaling_present_flag. The first information can be referred to as a first flag, information about whether syntax elements being used for interslices are present in the figure header, a flag about whether syntax elements being used for interslices are present in the figure header, information about whether slices in the current figure are interslices, or a flag for whether slices are interslices. The second information can be referred to as a second flag, information about whether syntax elements being used for intraslices are present in the figure header, a flag about whether syntax elements being used for intraslices are present in the figure header, information about whether slices in the current figure are intra-slices, or a flag for whether slices are intra-slices.

[0195] However, in the case where only the information necessary for the intraprediction operation is included in the corresponding figure header such as only the intracoded slice is included in the figure, the entropy encoder 240 of the encoding apparatus can determine the value of the first information as 0, and can set the value of the second information as 1. Furthermore, in the case where only the information required for the interprediction operation is included in the corresponding figure header as only the intercoded slice is included in the figure, the value of the first information can be determined as 1, and the value of the second information can be determined as 0. Correspondingly, if the value of the first information is 0, all slices in the current figure can have a slice type I. If the value of the second information information is 0, all slices in the current figure may have slice type P or slice type B. Herein, the information required for the intraprediction operation may include a syntax element being used for intraslice decoding, and The information required for the interprediction operation may include the syntax element being used for decoding the interslice.

[0196] As another example, if all slices in the current figure have slice type I, the entropy encoder 240 of the encoding apparatus may determine the value of the slice type information as 0, if all slices in the figure current have slice type P or slice type B, the entropy encoder 240 of the encoding apparatus may determine the value of the slice type information as 1. If all slices in the current figure have slice type I , slice type P and/or slice type B (that is, the slice types of the slices in the figure are mixed), the entropy encoder 240 of the encoding apparatus may determine the value of the slice type information as 2 In this case, the slice type information may correspond to slice_type_idc.

[0197] As yet another example, if all slices in the current figure have the same slice type, the entropy encoder 240 of the encoding apparatus may determine the value of the slice type information as 0, and whether the slices in the current figure have different slice types, the entropy encoder 240 of the encoding apparatus may determine the value of the slice type information as 1. In this case, the slice type information may correspond to mixed_slice_signaling_present_flag.

[0198] If the value of slice type information is determined to be 0, information about whether intraslice is included in slices can be included in the corresponding figure header. Information about whether intraslice is included in slices can correspond to intra_slice_only_flag. If all slices in the figure have slice type I, the entropy encoder 240 of the encoding apparatus may determine the value of information about whether the intraslice is included in the slices as 1, determine the value of information about whether the syntax elements being used for the interslice are present in the figure header as 1, and determine the value of the information about whether the syntax elements being used for the interslice are present in the figure header as 0. If the slice type of all the slices in the figure is the slice type P and/or B, the entropy encoder 240 of the encoding apparatus may determine the value of the information about whether the intraslice is included in the slices as 0, determine the value of the information about whether the syntax elements being used for the interslice are present in the figure header as 0 and determine the value of information about whether the syntax elements being used for the interslice are present in the figure header as 1.

[0199] The entropy encoder 240 of the encoding apparatus can encode image information including first information, second information, and slice type information together with residual information and prediction-related information (S830). For example, image information may include partitioning-related information, prediction mode information, residual information, loop filtering-related information, first information, second information, and slice type information, and may include various elements of their syntax. As an example, image information may include information about multiple parameter sets, such as an adaptation parameter set (APS), figure parameter set (PPS), sequence parameter set (SPS), or image parameter set. video (VPS). Furthermore, picture information may include various pieces of information, such as picture header syntax, picture header structure syntax, slice header syntax, and coding unit syntax. The first information, second information, slice type information, information required for the intraprediction operation, and information required for the interprediction operation described previously may be included in the syntax in the figure header.

[0200] The information encoded by the entropy encoder 240 of the encoding apparatus may be output in the form of a bit stream. The bit stream can be transmitted over a network or a storage medium.

[0201] Figures 10 and 11 schematically illustrate a video/image decoding method and an example of related components according to an embodiment of the present document.

[0202] The video/image decoding method disclosed in Figure 10 can be performed by the (video/image) decoding apparatus 300 disclosed in Figures 3 and 11. Specifically, for example, S1000 to S1020 of Figure 10 can be performed by the entropy decoder 310 of the decoding apparatus, and S1030 may be performed by the predictor 330 of the decoding apparatus 300. The video/image decoding method disclosed in Figure 10 may include the previously described embodiments of the present document.

[0203] Referring to Figures 10 and 11, the entropy decoder 310 of the decoding apparatus can obtain image information from a bit stream (S1000). Image information may include a figure header related to the current figure. The current figure may include a plurality of slices.

[0204] However, the entropy decoder 310 of the decoding apparatus may parse, from the figure header, a first flag representing whether information necessary for an interprediction operation for a decoding process is present in the figure header related to the current figure (S1010). Furthermore, the entropy decoder 310 of the decoding apparatus may parse, from the picture header, a second flag that represents whether information necessary for an intraprediction operation for the decoding process is present in the picture header related to the current picture ( S1020). In this document, the first flag and the second flag may correspond to intra_signaling_present_flag, inter_signaling_present_flag, slice_type_idc, mixed_slice_signaling_present_flag, intra_slice_only_flag, IntraSignalingPresentFlag and/or InterSignalingPresentFlag described previously. The entropy decoder 310 of the decoding apparatus may parse syntax elements included in the picture header of the picture information based on any picture header syntax in Tables 2, 4, and 6 as previously described.

[0205] The decoding apparatus may generate prediction samples by performing at least one of intraprediction or interprediction for slices in the current figure based on the first flag, the second flag, and slice type information (S1030).

[0206] Specifically, the entropy decoder 310 of the decoding apparatus may analyze (or obtain) at least one of the information necessary for the intraprediction operation and/or the information necessary for the interprediction operation for the decoding process from the figure header related to the current figure based on the first flag, the second flag, and/or slice type information. The predictor 330 of the decoding apparatus may generate prediction samples by performing intra-prediction and/or inter-prediction based on at least one of the information required for the intra-prediction operation or the information for the inter-prediction. Herein, the information necessary for the intraprediction operation may include a syntax element being used for decoding an intraslice, and the information necessary for the interprediction operation may include a syntax element being used for decoding an interslice.

[0207] As an example, if the value of the first flag is 0, the entropy decoder 310 of the decoding apparatus may determine (or decide) that the syntax elements being used for interprediction are not present in the figure header, and can parse only the information required for the intraprediction operation from the figure header. If the value of the first flag is 1, the entropy decoder 310 of the decoding apparatus can determine (or decide) that the syntax elements being used for the interprediction are present in the figure header, and can parse the information necessary for the operation. of interprediction from the figure header. In this case, the first flag may correspond to inter_signaling_present_flag.

[0208] Furthermore, if the value of the second flag is 0, the entropy decoder 310 of the decoding apparatus may determine (or decide) that the syntax elements being used for intraprediction are not present in the figure header, and may parse only the information necessary for the interprediction operation from the figure header. If the value of the second flag is 1, the entropy decoder 310 of the decoding apparatus may determine (or decide) that the syntax elements being used for the intraprediction are present in the figure header, and may parse the information necessary for the operation. of intraprediction from the figure header. In this case, the second flag may correspond to intra_signaling_present_flag.

[0209] If the value of the first flag is 0, the decoding apparatus may determine that all slices in the current figure have slice type I. If the value of the first flag is 1, the decoding apparatus may determine that 0 or more slices in the current figure have slice type P or slice B. In other words, if the value of the first flag is 1, the slice having slice type P or slice B may be included or may not be included in the current figure .

[0210] Furthermore, if the value of the second flag is 0, the decoding apparatus may determine that all slices in the current figure have slice type P or slice B. If the value of the second flag is 1, the decoding apparatus may can determine that 0 or more slices in the current figure have slice type I. In other words, if the value of the second flag is 1, the slice having slice type I may be included or may not be included in the current figure.

[0211] As another example, if the value of the slice type information is 0, the entropy decoder 310 of the decoding apparatus may determine that all slices in the current figure have a slice type I, and may analyze only those information necessary for the intraprediction operation. If the slice type information is 1, the entropy decoder 310 of the decoding apparatus can determine that all slices in the corresponding figure have slice type P or slice type B, and can analyze only the information necessary to the interprediction operation from the figure header. If the information value for the slice type is 2, the entropy decoder 310 of the decoding apparatus may determine that the slices in the corresponding figure have the slice type where slice type I, slice type P and/or The slice type B are mixed, and can parse all the information required for the interprediction operation and the information required for the intraprediction operation from the figure header. In this case, the slice type information may correspond to slice_type_idc.

[0212] As yet another example, the entropy decoder 310 of the decoding apparatus may determine that all slices in the current figure have the same slice type if the slice type information value is determined to be 0, and may determine which slices in the current figure have different slice types if the value of the slice type information is set to 1. In this case, the slice type information may correspond to mixed_slice_signalling_present_flag.

[0213] If the value of the slice type information is determined to be 0, the entropy decoder 310 of the decoding apparatus can analyze information about whether the intraslice is included in the slices from the figure header. Information about whether intraslice is included in slices can correspond to intra_slice_only_flag as described previously. If the value of information about whether intraslice is included in slices is 1, all slices in the figure can have slice type I.

[0214] If the value of the information about whether the intraslice is included in the slices is 1, the entropy decoder 310 of the encoding apparatus can parse only the information necessary for the intraprediction operation from the figure header. If the value of the information about whether the intraslice is included in the slices is 0, the entropy decoder 310 of the decoding apparatus can analyze only the information necessary for the interprediction operation from the figure header.

[0215] If the value of the slice type information is 1, the entropy decoder 310 of the decoding apparatus can analyze all the information necessary for the interprediction operation and the information necessary for the intraprediction operation from the slice header. figure.

[0216] However, the residual processor 320 of the decoding apparatus may generate residual samples based on the residual information obtained by the entropy decoder 310.

[0217] The adder 340 of the decoding apparatus may generate reconstructed samples based on the prediction samples generated by the predictor 330 and the residual samples generated by the residual processor 320. Furthermore, the adder 340 of the decoding apparatus may generate a reconstructed figure (block reconstructed) based on the reconstructed samples.

[0218] Subsequently, as necessary, in order to enhance the subjective/objective figure quality, loop filtering procedures, such as deblocking filtering, SÃO and/or AFL procedures, can be applied to the reconstructed figure.

[0219] 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 disclosure 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 the present disclosure.

[0220] The aforementioned method according to the present disclosure may be in the form of software, and the encoding apparatus and/or the decoding apparatus according to the present disclosure 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.

[0221] When the embodiments in the present disclosure 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 embodiments described in the present disclosure 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.

[0222] Furthermore, the decoding apparatus and the encoding apparatus to which embodiments of the present disclosure are applied may be included in a multimedia broadcast transceiver, a mobile communications 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.

[0223] Furthermore, the processing method to which the embodiments of the present disclosure 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 according to the present disclosure 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.

[0224] Furthermore, embodiments of the present disclosure may be embodied as a computer program product by program code, and the program code may be executed on the computer in accordance with embodiments of the present disclosure. Program code can be stored on a computer-readable carrier.

[0225] Figure 12 represents an example of a content streaming system to which the embodiment of the present disclosure can be applied.

[0226] Referring to Figure 12, the content streaming system to which embodiments of the present disclosure 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.

[0227] 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.

[0228] The bit stream may be generated by a coding method or a bit stream generation method to which embodiments of the present disclosure are applied. And the streaming server can temporarily store the bitstream in a process to transmit or receive the bitstream.

[0229] The streaming server transmits multimedia data to the user equipment based on a user request through 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.

[0230] 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.

[0231] 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.

[0232] 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 (3)

1. Decoding apparatus for decoding an image, the decoding apparatus 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: receive a bit stream comprising image information, the image information including a picture header related to a current picture, the current picture including slices; analyze, from the figure header, a first flag related to whether the information for an interslice is present in the figure header, wherein a value of the first flag being equal to 1 is related to the fact that the information for a interslice is present in the figure header, where the first flag being equal to 1 indicates that the current figure includes one or more interslices; analyze, from the figure header, a second flag relating to whether information for an intraslice is present in the figure header, wherein a value of the second flag being equal to 1 is related to whether the information for the intraslice is present in the figure header, where the second flag being equal to 1 indicates that the current figure includes one or more intraslices; and generating prediction samples by performing at least one of an intraprediction or an interprediction in blocks on the slices of the current figure based on the first flag and the second flag, wherein based on the value of the first flag being equal to 1, the information for the interslice is comprised in the figure header, wherein the information for the interslice includes a syntax element that represents a difference between the base-2 logarithm of a minimum size resulting from quadtree splitting and the base-2 logarithm of a minimum size of coding block in the current figure interslice, and wherein based on a value of the second flag being equal to 1, the information for the intraslice is comprised in the figure header, wherein the information for the intraslice includes a syntax element that represents a difference between the base 2 logarithm of a minimum size resulting from quadtree splitting and the base 2 logarithm of a minimum coding block size in the intraslice in the current figure. 2. Coding apparatus for encoding an image, CHARACTERIZED by the fact that the encoding apparatus comprises: a memory; and at least one processor connected to the memory, the at least one processor configured to: determine types of slices in a current figure; generate a first flag related to whether information for an interslice is present in a figure header related to the current figure, wherein a value of the first flag being equal to 1 is related to the fact that information for the interslice is present in the figure header, where the first flag being equal to 1 indicates that the current figure includes one or more interslices; generate a second flag related to whether information for an intra-slice is present in the figure header related to the current figure, wherein a value of the second flag being equal to 1 is related to the fact that information for the intra-slice is present in the figure header, where the second flag being equal to 1 indicates that the current figure includes one or more intraslices; and encoding image information including the first flag and the second flag; wherein the first flag and the second flag are comprised in the figure header of the image information, wherein based on the value of the first flag being equal to 1, the information for the interslice is comprised in the figure header, wherein the information for the interslice include a syntax element that represents a difference between the base-2 logarithm of a minimum size resulting from quadtree splitting and the base-2 logarithm of a minimum coding block size in the interslice in the current figure, and in that based on a value of the second flag being equal to 1, the information for the intraslice is comprised in the figure header, wherein the information for the intraslice includes a syntax element representing a difference between the base 2 logarithm of a minimum size resulting from quadtree splitting and the base 2 logarithm of a minimum coding block size in the intraslice in the current figure. 3. Apparatus for transmitting data to an image, CHARACTERIZED by the fact that the apparatus comprises: at least one processor configured to obtain a bit stream for the image, wherein the bit stream is generated based on determining types of slices in a current figure, generate a first flag related to whether information for an interslice is present in a figure header related to the current figure, wherein a value of the first flag being equal to 1 is related to the fact that the information for the interslice is present in the figure header, where the first flag being equal to 1 is indicating that the current image includes one or more interslices, generate a second flag related to whether the information for an intraslice is present in the header of figure related to the current figure, wherein a value of the second flag being equal to 1 is related to the fact that if information for the intraslice is present in the figure header, wherein the second flag being equal to 1 indicates that the figure current includes one or more intraslices and encodes image information including the first flag and the second flag; and a transmitter configured to transmit the data comprising the bit stream, wherein the first flag and the second flag are comprised in the figure header of the image information, wherein based on the value of the first flag being equal to 1, the information for the interslice is comprised in the figure header, wherein the information for the interslice includes a syntax element that represents a difference between the base 2 logarithm of a minimum size resulting from quadtree division and the base 2 logarithm of a minimum size minimum coding block in the current figure interslice, and wherein based on a value of the second flag being equal to 1, the information for the intraslice is comprised in the figure header, wherein the information for the intraslice includes an element of syntax that represents a difference between the base-2 logarithm of a minimum size resulting from quadtree splitting and the base-2 logarithm of a minimum coding block size in the intraslice in the current figure.