WO2020180133A1 - Procédé et appareil de codage/décodage de vidéo et procédé de transmission de flux binaire - Google Patents

Procédé et appareil de codage/décodage de vidéo et procédé de transmission de flux binaire Download PDF

Info

Publication number
WO2020180133A1
WO2020180133A1 PCT/KR2020/003128 KR2020003128W WO2020180133A1 WO 2020180133 A1 WO2020180133 A1 WO 2020180133A1 KR 2020003128 W KR2020003128 W KR 2020003128W WO 2020180133 A1 WO2020180133 A1 WO 2020180133A1
Authority
WO
WIPO (PCT)
Prior art keywords
current block
intra prediction
syntax element
intra
prediction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/KR2020/003128
Other languages
English (en)
Korean (ko)
Inventor
허진
최장원
이령
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
LG Electronics Inc
Original Assignee
LG Electronics Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by LG Electronics Inc filed Critical LG Electronics Inc
Publication of WO2020180133A1 publication Critical patent/WO2020180133A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/11—Selection of coding mode or of prediction mode among a plurality of spatial predictive coding modes
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/18—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being a set of transform coefficients
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/593—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving spatial prediction techniques
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/70—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals characterised by syntax aspects related to video coding, e.g. related to compression standards

Definitions

  • the present disclosure relates to an image encoding/decoding method, an apparatus, and a method of transmitting a bitstream, and more particularly, a method and apparatus for encoding/decoding an image using an integrated syntax element, and an image encoding of the present disclosure. It relates to a method of transmitting a bitstream generated by a method/apparatus.
  • An object of the present disclosure is to provide an image encoding/decoding method and apparatus with improved encoding/decoding efficiency.
  • an object of the present disclosure is to provide a method and apparatus for encoding/decoding an image using an integrated syntax element.
  • an object of the present disclosure is to provide a method and apparatus for encoding/decoding an intra-predicted image using an integrated syntax element.
  • an object of the present disclosure is to provide a method for transmitting a bitstream generated by an image encoding method or apparatus according to the present disclosure.
  • an object of the present disclosure is to provide a recording medium storing a bitstream generated by an image encoding method or apparatus according to the present disclosure.
  • an object of the present disclosure is to provide a recording medium storing a bitstream that is received and decoded by an image decoding apparatus according to the present disclosure and used for image restoration.
  • settings of at least two or more different intra prediction techniques may be determined using a single syntax element. Specifically, settings of two or more different intra prediction techniques may be determined based on a single syntax element. By determining settings of two or more different intra prediction techniques using a single syntax element, it is possible to simplify a syntax encoding/decoding process related to intra prediction and increase encoding efficiency.
  • an image decoding method based on information on a prediction mode of a current block, determining whether a prediction mode of the current block is an intra prediction mode, wherein the prediction mode of the current block is intra prediction In the case of the mode, parsing a syntax element related to intra prediction of the current block and generating a prediction block for the current block using the parsed syntax element, wherein the The syntax element related to intra prediction of the current block may include a first syntax element used to determine an intra prediction setting of at least two different intra prediction techniques.
  • the two or more different intra prediction techniques may include at least two or more of Most Probable Mode (MPM), multi-reference line intra prediction (MRL), and Intra Sub-Partitions (ISP). I can.
  • MPM Most Probable Mode
  • MLM multi-reference line intra prediction
  • ISP Intra Sub-Partitions
  • the first syntax element may be used to determine at least two of whether to apply MPM to the current block, a reference sample line used when performing MRL, and whether to apply an ISP.
  • the first syntax element when an ISP is applied to the current block, the first syntax element may be used to determine an ISP division direction for the current block.
  • a binary value allocated to the first syntax element may be determined based on at least one of an MRL applicable condition and an ISP applicable condition for the current block.
  • the MRL applicable condition and the ISP applicable condition may be determined based on at least one of a size of the current block, a maximum transform size of a block, and a minimum transform size of a block.
  • the first syntax element is used to determine whether to apply the MPM to the current block, a reference sample line used when performing the MRL, and whether to apply the ISP, but whether to apply the MPM Is assigned a higher priority to the binary value of the first syntax element.
  • the binary value of the first syntax element may be allocated with a minimum number of digits.
  • the parsing of a syntax element related to intra prediction of the current block includes: parsing an MPM flag for the current block and based on the MPM flag value, the first syntax element Parsing, wherein the first syntax element may be used to determine whether to apply the ISP and a reference sample line used when performing the MRL for the current block.
  • the first syntax element may be parsed only when the MPM flag value indicates that MPM is applied to the current block.
  • An image decoding apparatus includes a memory and at least one processor, wherein the at least one processor includes, based on information on a prediction mode of a current block, a prediction mode of the current block being an intra prediction mode It is determined whether or not, and when the prediction mode of the current block is an intra prediction mode, a syntax element related to intra prediction of the current block is parsed, and a prediction block for the current block is determined using the parsed syntax element.
  • the syntax element related to intra prediction of the current block may include a first syntax element used to determine an intra prediction setting of at least two different intra prediction techniques.
  • An image encoding method includes determining whether a prediction mode of the current block is an intra prediction mode, and when the prediction mode of the current block is an intra prediction mode, intra prediction is performed to Generating a prediction block for, and encoding a syntax element related to intra prediction of the current block, wherein the syntax element related to intra prediction of the current block is set to intra prediction of at least two different intra prediction techniques It may include a first syntax element used to determine
  • the two or more different intra prediction techniques may include at least two or more of Most Probable Mode (MPM), multi-reference line intra prediction (MRL), and Intra Sub-Partitions (ISP).
  • MPM Most Probable Mode
  • MRL multi-reference line intra prediction
  • ISP Intra Sub-Partitions
  • the first syntax element may be used to determine at least two of whether to apply MPM to the current block, a reference sample line used when performing MRL, and whether to apply an ISP.
  • a transmission method may transmit a bitstream generated by the image encoding apparatus or image encoding method of the present disclosure.
  • a computer-readable recording medium may store a bitstream generated by the image encoding method or image encoding apparatus of the present disclosure.
  • an image encoding/decoding method and apparatus with improved encoding/decoding efficiency may be provided.
  • a method and apparatus for encoding/decoding an image using an integrated syntax element may be provided.
  • a method and apparatus for encoding/decoding an intra-predicted image using an integrated syntax element may be provided.
  • a method for transmitting a bitstream generated by an image encoding method or apparatus according to the present disclosure may be provided.
  • a recording medium storing a bitstream generated by an image encoding method or apparatus according to the present disclosure may be provided.
  • a recording medium may be provided that stores a bitstream that is received and decoded by the image decoding apparatus according to the present disclosure and used for image restoration.
  • FIG. 1 is a diagram schematically illustrating a video coding system to which an embodiment according to the present disclosure can be applied.
  • FIG. 2 is a diagram schematically illustrating an image encoding apparatus to which an embodiment according to the present disclosure can be applied.
  • FIG. 3 is a diagram schematically illustrating an image decoding apparatus to which an embodiment according to the present disclosure can be applied.
  • FIG. 4 is a flowchart illustrating a process of generating a prediction block (predicted block) of a current block by performing intra prediction.
  • FIG. 5 is a diagram for describing an image decoding method according to an embodiment of the present disclosure.
  • FIG. 6 is a diagram for describing an image encoding method according to an embodiment of the present disclosure.
  • FIG. 7 is a diagram for explaining a syntax encoding/decoding method according to a conventional method.
  • FIG. 8 is a diagram illustrating a structure of a bitstream reflecting a syntax encoding/decoding method according to a conventional method.
  • FIG. 9 is another diagram for describing an image encoding/decoding method according to an embodiment of the present disclosure.
  • FIG. 10 is a diagram for describing an image encoding/decoding method according to another embodiment of the present disclosure.
  • FIG. 11 is a diagram illustrating a structure of a bitstream reflecting a syntax encoding/decoding method according to another embodiment of the present disclosure.
  • FIG. 12 is a diagram illustrating a content streaming system to which an embodiment of the present disclosure can be applied.
  • first and second are used only for the purpose of distinguishing one component from other components, and do not limit the order or importance of the components unless otherwise stated. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment is a first component in another embodiment. It can also be called.
  • components that are distinguished from each other are intended to clearly describe each feature, and do not necessarily mean that the components are separated. That is, a plurality of components may be integrated to be formed in one hardware or software unit, or one component may be distributed in a plurality of hardware or software units. Therefore, even if not stated otherwise, such integrated or distributed embodiments are also included in the scope of the present disclosure.
  • components described in various embodiments do not necessarily mean essential components, and some may be optional components. Accordingly, an embodiment consisting of a subset of components described in an embodiment is also included in the scope of the present disclosure. In addition, embodiments including other elements in addition to the elements described in the various embodiments are included in the scope of the present disclosure.
  • the present disclosure relates to encoding and decoding of an image, and terms used in the present disclosure may have a common meaning commonly used in the technical field to which the present disclosure belongs unless newly defined in the present disclosure.
  • a “picture” generally refers to a unit representing one image in a specific time period
  • a slice/tile is a coding unit constituting a part of a picture
  • one picture is one It may be composed of more than one slice/tile.
  • a slice/tile may include one or more coding tree units (CTU).
  • pixel or "pel” may mean a minimum unit constituting one picture (or image).
  • sample may be used as a term corresponding to a pixel.
  • a sample may generally represent a pixel or a value of a pixel, may represent only a pixel/pixel value of a luma component, or may represent only a pixel/pixel value of a chroma component.
  • unit may represent a basic unit of image processing.
  • the unit may include at least one of a specific area of a picture and information related to the corresponding area.
  • the unit may be used interchangeably with terms such as “sample array”, “block”, or “area” depending on the case.
  • the MxN block may include samples (or sample arrays) consisting of M columns and N rows, or a set (or array) of transform coefficients.
  • current block may mean one of “current coding block”, “current coding unit”, “coding object block”, “decoding object block”, or “processing object block”.
  • current block may mean “current prediction block” or “prediction target block”.
  • transformation inverse transformation
  • quantization inverse quantization
  • current block may mean “current transform block” or “transform target block”.
  • filtering is performed, “current block” may mean “block to be filtered”.
  • FIG. 1 shows a video coding system according to this disclosure.
  • a video coding system may include an encoding device 10 and a decoding device 20.
  • the encoding device 10 may transmit the encoded video and/or image information or data in a file or streaming format to the decoding device 20 through a digital storage medium or a network.
  • the encoding apparatus 10 may include a video source generator 11, an encoder 12, and a transmission unit 13.
  • the decoding apparatus 20 may include a receiving unit 21, a decoding unit 22, and a rendering unit 23.
  • the encoder 12 may be referred to as a video/image encoder, and the decoder 22 may be referred to as a video/image decoder.
  • the transmission unit 13 may be included in the encoding unit 12.
  • the receiving unit 21 may be included in the decoding unit 22.
  • the rendering unit 23 may include a display unit, and the display unit may be configured as a separate device or an external component.
  • the video source generator 11 may acquire a video/image through a process of capturing, synthesizing, or generating a video/image.
  • the video source generator 11 may include a video/image capturing device and/or a video/image generating device.
  • the video/image capture device may include, for example, one or more cameras, a video/image archive including previously captured video/images, and the like.
  • the video/image generating device may include, for example, a computer, a tablet and a smartphone, and may (electronically) generate a video/image.
  • a virtual video/image may be generated through a computer or the like, and in this case, a video/image capturing process may be substituted as a process of generating related data.
  • the encoder 12 may encode an input video/image.
  • the encoder 12 may perform a series of procedures such as prediction, transformation, and quantization for compression and encoding efficiency.
  • the encoder 12 may output encoded data (coded video/image information) in a bitstream format.
  • the transmission unit 13 may transmit the encoded video/image information or data output in the form of a bitstream to the receiving unit 21 of the decoding apparatus 20 through a digital storage medium or a network in a file or streaming form.
  • Digital storage media may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, and SSD.
  • the transmission unit 13 may include an element for generating a media file through a predetermined file format, and may include an element for transmission through a broadcast/communication network.
  • the receiving unit 21 may extract/receive the bitstream from the storage medium or network and transmit it to the decoding unit 22.
  • the decoder 22 may decode the video/image by performing a series of procedures such as inverse quantization, inverse transformation, and prediction corresponding to the operation of the encoder 12.
  • the rendering unit 23 may render the decoded video/image.
  • the rendered video/image may be displayed through the display unit.
  • FIG. 2 is a diagram schematically illustrating an image encoding apparatus to which an embodiment according to the present disclosure can be applied.
  • the image encoding apparatus 100 includes an image segmentation unit 110, a subtraction unit 115, a transform unit 120, a quantization unit 130, an inverse quantization unit 140, and an inverse transform unit ( 150), an addition unit 155, a filtering unit 160, a memory 170, an inter prediction unit 180, an intra prediction unit 185, and an entropy encoding unit 190.
  • the inter prediction unit 180 and the intra prediction unit 185 may be collectively referred to as a “prediction unit”.
  • the transform unit 120, the quantization unit 130, the inverse quantization unit 140, and the inverse transform unit 150 may be included in a residual processing unit.
  • the residual processing unit may further include a subtraction unit 115.
  • All or at least some of the plurality of constituent units constituting the image encoding apparatus 100 may be implemented as one hardware component (eg, an encoder or a processor) according to embodiments.
  • the memory 170 may include a decoded picture buffer (DPB), and may be implemented by a digital storage medium.
  • DPB decoded picture buffer
  • the image splitter 110 may divide an input image (or picture, frame) input to the image encoding apparatus 100 into one or more processing units.
  • the processing unit may be referred to as a coding unit (CU).
  • the coding unit is a coding tree unit (CTU) or a largest coding unit (LCU) recursively according to a QT/BT/TT (Quad-tree/binary-tree/ternary-tree) structure ( It can be obtained by dividing recursively.
  • one coding unit may be divided into a plurality of coding units of a deeper depth based on a quad tree structure, a binary tree structure, and/or a ternary tree structure.
  • a quad tree structure may be applied first, and a binary tree structure and/or a ternary tree structure may be applied later.
  • the coding procedure according to the present disclosure may be performed based on the final coding unit that is no longer divided.
  • the largest coding unit may be directly used as the final coding unit, or a coding unit of a lower depth obtained by dividing the largest coding unit may be used as the final cornet unit.
  • the coding procedure may include a procedure such as prediction, transformation, and/or restoration described later.
  • the processing unit of the coding procedure may be a prediction unit (PU) or a transform unit (TU).
  • Each of the prediction unit and the transform unit may be divided or partitioned from the final coding unit.
  • the prediction unit may be a unit of sample prediction
  • the transform unit may be a unit for inducing a transform coefficient and/or a unit for inducing a residual signal from the transform coefficient.
  • the prediction unit (inter prediction unit 180 or intra prediction unit 185) performs prediction on a block to be processed (current block), and generates a predicted block including prediction samples for the current block. Can be generated.
  • the prediction unit may determine whether intra prediction or inter prediction is applied in units of the current block or CU.
  • the prediction unit may generate various information on prediction of the current block and transmit it to the entropy encoding unit 190.
  • the information on prediction may be encoded by the entropy encoding unit 190 and output in the form of a bitstream.
  • the intra prediction unit 185 may predict the current block by referring to samples in the current picture.
  • the referenced samples may be located in a neighborhood of the current block or may be located away from each other according to an intra prediction mode and/or an intra prediction technique.
  • the intra prediction modes 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 and a planar mode (Planar mode).
  • the directional mode may include, for example, 33 directional prediction modes or 65 directional prediction modes, depending on the degree of detail of the prediction direction. However, this is an example, and more or less directional prediction modes may be used depending on the setting.
  • the intra prediction unit 185 may determine a prediction mode applied to the current block by using the prediction mode applied to the neighboring block.
  • the inter prediction unit 180 may derive a predicted block for the current block based on a reference block (reference sample array) specified by a motion vector on the reference picture.
  • motion information may be predicted in units of blocks, subblocks, or samples based on a correlation between motion information between a neighboring block and a current block.
  • the motion information may include a motion vector and a reference picture index.
  • the motion information may further include inter prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.) information.
  • the neighboring block may include a spatial neighboring block existing in the current picture and a temporal neighboring block existing in the reference picture.
  • the reference picture including the reference block and the reference picture including the temporal neighboring block may be the same or different from each other.
  • the temporal neighboring block may be referred to as a collocated reference block, a collocated CU (colCU), or the like.
  • a reference picture including the temporal neighboring block may be referred to as a collocated picture (colPic).
  • the inter prediction unit 180 constructs a motion information candidate list based on neighboring blocks, and provides information indicating which candidate is used to derive a motion vector and/or a reference picture index of the current block. Can be generated. Inter prediction may be performed based on various prediction modes.
  • the inter prediction unit 180 may use motion information of a neighboring block as motion information of a current block.
  • a residual signal may not be transmitted.
  • motion vector prediction (MVP) mode motion vectors of neighboring blocks are used as motion vector predictors, and indicators for motion vector difference and motion vector predictors ( indicator) to signal the motion vector of the current block.
  • the motion vector difference may mean a difference between a motion vector of a current block and a motion vector predictor.
  • the prediction unit may generate a prediction signal based on various prediction methods and/or prediction techniques to be described later.
  • the prediction unit may apply intra prediction or inter prediction for prediction of the current block, and may simultaneously apply intra prediction and inter prediction.
  • a prediction method in which intra prediction and inter prediction are applied simultaneously for prediction of a current block may be called combined inter and intra prediction (CIIP).
  • the prediction unit may perform intra block copy (IBC) for prediction of the current block.
  • the intra block copy may be used for content image/movie coding such as games, such as, for example, screen content coding (SCC).
  • IBC is a method of predicting a current block by using a reference block in a current picture at a distance from the current block by a predetermined distance. When IBC is applied, the position of the reference block in the current picture may be encoded as a vector (block vector) corresponding to the predetermined distance.
  • the prediction signal generated through the prediction unit may be used to generate a reconstructed signal or may be used to generate a residual signal.
  • the subtraction unit 115 subtracts the prediction signal (predicted block, prediction sample array) output from the prediction unit from the input image signal (original block, original sample array), and subtracts a residual signal (remaining block, residual sample array). ) Can be created.
  • the generated residual signal may be transmitted to the converter 120.
  • the transform unit 120 may generate transform coefficients by applying a transform technique to the residual signal.
  • the transformation technique uses at least one of DCT (Discrete Cosine Transform), DST (Discrete Sine Transform), KLT (Karhunen-Loeve Transform), GBT (Graph-Based Transform), or CNT (Conditionally Non-linear Transform).
  • DCT Discrete Cosine Transform
  • DST Discrete Sine Transform
  • KLT Kerhunen-Loeve Transform
  • GBT Graph-Based Transform
  • CNT Supplementally Non-linear Transform
  • GBT refers to the transformation obtained from this graph when the relationship information between pixels is expressed in a graph.
  • CNT refers to a transform obtained based on generating a prediction signal using all previously reconstructed pixels.
  • the conversion process may be applied to a block of pixels having the same size of a square, or may be applied to a block of a variable size other than a square.
  • the quantization unit 130 may quantize the transform coefficients and transmit the quantization to the entropy encoding unit 190.
  • the entropy encoding unit 190 may encode a quantized signal (information on quantized transform coefficients) and output it as a bitstream.
  • the information on the quantized transform coefficients may be called residual information.
  • the quantization unit 130 may rearrange the quantized transform coefficients in the form of a block into a one-dimensional vector form based on a coefficient scan order, and the quantized transform coefficients in the form of the one-dimensional vector It is also possible to generate information about transform coefficients.
  • the entropy encoding unit 190 may perform various encoding methods such as exponential Golomb, context-adaptive variable length coding (CAVLC), and context-adaptive binary arithmetic coding (CABAC).
  • the entropy encoding unit 190 may encode together or separately information necessary for video/image restoration (eg, values of syntax elements) in addition to quantized transform coefficients.
  • the encoded information (eg, encoded video/video information) may be transmitted or stored in a bitstream format in units of network abstraction layer (NAL) units.
  • the video/video information may further include information on various parameter sets, such as an adaptation parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS).
  • the video/video information may further include general constraint information.
  • the signaling information, transmitted information, and/or syntax elements mentioned in the present disclosure may be encoded through the above-described encoding procedure and included in the bitstream.
  • the bitstream may be transmitted through a network or may be stored in a digital storage medium.
  • the network may include a broadcasting network and/or a communication network
  • the digital storage medium may include various storage media such as USB, SD, CD, DVD, Blu-ray, HDD, and SSD.
  • a transmission unit (not shown) for transmitting the signal output from the entropy encoding unit 190 and/or a storage unit (not shown) for storing may be provided as an inner/outer element of the image encoding apparatus 100, or transmission The unit may be provided as a component of the entropy encoding unit 190.
  • the quantized transform coefficients output from the quantization unit 130 may be used to generate a residual signal.
  • a residual signal residual block or residual samples
  • inverse quantization and inverse transform residual transforms
  • the addition unit 155 adds the reconstructed residual signal to the prediction signal output from the inter prediction unit 180 or the intra prediction unit 185 to obtain a reconstructed signal (a reconstructed picture, a reconstructed block, and a reconstructed sample array). Can be generated.
  • a reconstructed signal (a reconstructed picture, a reconstructed block, and a reconstructed sample array).
  • the predicted block may be used as a reconstructed block.
  • the addition unit 155 may be referred to as a restoration unit or a restoration block generation unit.
  • the generated reconstructed signal may be used for intra prediction of the next processing target block in the current picture, and may be used for inter prediction of the next picture through filtering as described later.
  • LMCS luma mapping with chroma scaling
  • the filtering unit 160 may apply filtering to the reconstructed signal to improve subjective/objective image quality.
  • the filtering unit 160 may generate a modified reconstructed picture by applying various filtering methods to the reconstructed picture, and the modified reconstructed picture may be converted to the memory 170, specifically, the DPB of the memory 170. Can be saved on.
  • the various filtering methods may include, for example, deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, and the like.
  • the filtering unit 160 may generate a variety of filtering information and transmit it to the entropy encoding unit 190 as described later in the description of each filtering method.
  • the filtering information may be encoded by the entropy encoding unit 190 and output in the form of a bitstream.
  • the modified reconstructed picture transmitted to the memory 170 may be used as a reference picture in the inter prediction unit 180.
  • the image encoding apparatus 100 may avoid prediction mismatch between the image encoding apparatus 100 and the image decoding apparatus, and may improve encoding efficiency.
  • the DPB in the memory 170 may store a reconstructed picture modified to be used as a reference picture in the inter prediction unit 180.
  • the memory 170 may store motion information of a block from which motion information in a current picture is derived (or encoded) and/or motion information of blocks in a picture that have already been reconstructed.
  • the stored motion information may be transmitted to the inter prediction unit 180 to be used as motion information of spatial neighboring blocks or motion information of temporal neighboring blocks.
  • the memory 170 may store reconstructed samples of reconstructed blocks in the current picture, and may transmit the reconstructed samples to the intra prediction unit 185.
  • FIG. 3 is a diagram schematically illustrating an image decoding apparatus to which an embodiment according to the present disclosure can be applied.
  • the image decoding apparatus 200 includes an entropy decoding unit 210, an inverse quantization unit 220, an inverse transform unit 230, an addition unit 235, a filtering unit 240, and a memory 250. ), an inter prediction unit 260 and an intra prediction unit 265 may be included.
  • the inter prediction unit 260 and the intra prediction unit 265 may be collectively referred to as a “prediction unit”.
  • the inverse quantization unit 220 and the inverse transform unit 230 may be included in the residual processing unit.
  • All or at least some of the plurality of constituent units constituting the image decoding apparatus 200 may be implemented as one hardware component (eg, a decoder or a processor) according to embodiments.
  • the memory 170 may include a DPB and may be implemented by a digital storage medium.
  • the image decoding apparatus 200 receiving a bitstream including video/image information may reconstruct an image by performing a process corresponding to the process performed by the image encoding apparatus 100 of FIG. 1.
  • the image decoding apparatus 200 may perform decoding using a processing unit applied in the image encoding apparatus.
  • the processing unit of decoding may be, for example, a coding unit.
  • the coding unit may be a coding tree unit or may be obtained by dividing the largest coding unit.
  • the reconstructed image signal decoded and output through the image decoding apparatus 200 may be reproduced through a reproduction device (not shown).
  • the image decoding apparatus 200 may receive a signal output from the image encoding apparatus of FIG. 1 in the form of a bitstream.
  • the received signal may be decoded through the entropy decoding unit 210.
  • the entropy decoding unit 210 may parse the bitstream to derive information (eg, video/video information) necessary for image restoration (or picture restoration).
  • the video/video information may further include information on various parameter sets, such as an adaptation parameter set (APS), a picture parameter set (PPS), a sequence parameter set (SPS), or a video parameter set (VPS).
  • the video/video information may further include general constraint information.
  • the image decoding apparatus may additionally use information on the parameter set and/or the general restriction information to decode an image.
  • the signaling information, received information, and/or syntax elements mentioned in the present disclosure may be obtained from the bitstream by being decoded through the decoding procedure.
  • the entropy decoding unit 210 decodes information in the bitstream based on a coding method such as exponential Golomb coding, CAVLC, or CABAC, and a value of a syntax element required for image restoration, a quantized value of a transform coefficient related to a residual. Can be printed.
  • the CABAC entropy decoding method receives a bin corresponding to each syntax element in a bitstream, and includes information on the syntax element to be decoded, decoding information of the neighboring block and the block to be decoded, or information of the symbol/bin decoded in the previous step.
  • the context model is determined by using and, according to the determined context model, the probability of occurrence of bins is predicted to perform arithmetic decoding of the bins to generate a symbol corresponding to the value of each syntax element.
  • the CABAC entropy decoding method may update the context model using information of the decoded symbol/bin for the context model of the next symbol/bin after the context model is determined.
  • the entropy decoding unit 210 Among the information decoded by the entropy decoding unit 210, information on prediction is provided to the prediction unit (inter prediction unit 260 and intra prediction unit 265), and the register on which entropy decoding is performed by the entropy decoding unit 210 Dual values, that is, quantized transform coefficients and related parameter information may be input to the inverse quantization unit 220. In addition, information about filtering among information decoded by the entropy decoding unit 210 may be provided to the filtering unit 240.
  • a receiving unit for receiving a signal output from the image encoding device may be additionally provided as an inner/outer element of the image decoding device 200, or the receiving unit is provided as a component of the entropy decoding unit 210 It could be.
  • the video decoding apparatus may include an information decoder (video/video/picture information decoder) and/or a sample decoder (video/video/picture sample decoder).
  • the information decoder may include an entropy decoding unit 210, and the sample decoder includes an inverse quantization unit 220, an inverse transform unit 230, an addition unit 235, a filtering unit 240, a memory 250, It may include at least one of the inter prediction unit 260 and the intra prediction unit 265.
  • the inverse quantization unit 220 may inverse quantize the quantized transform coefficients and output transform coefficients.
  • the inverse quantization unit 220 may rearrange the quantized transform coefficients into a two-dimensional block shape. In this case, the rearrangement may be performed based on a coefficient scan order performed by the image encoding apparatus.
  • the inverse quantization unit 220 may perform inverse quantization on quantized transform coefficients by using a quantization parameter (eg, quantization step size information) and obtain transform coefficients.
  • a quantization parameter eg, quantization step size information
  • the inverse transform unit 230 may inverse transform the transform coefficients to obtain a residual signal (residual block, residual sample array).
  • the prediction unit may perform prediction on the current block and generate a predicted block including prediction samples for the current block.
  • the prediction unit may determine whether intra prediction or inter prediction is applied to the current block based on the prediction information output from the entropy decoding unit 210, and determine a specific intra/inter prediction mode (prediction technique). I can.
  • the prediction unit can generate the prediction signal based on various prediction methods (techniques) described later.
  • the intra prediction unit 265 may predict the current block by referring to samples in the current picture.
  • the description of the intra prediction unit 185 may be equally applied to the intra prediction unit 265.
  • the inter prediction unit 260 may derive a predicted block for the current block based on a reference block (reference sample array) specified by a motion vector on the reference picture.
  • motion information may be predicted in units of blocks, subblocks, or samples based on a correlation between motion information between a neighboring block and a current block.
  • the motion information may include a motion vector and a reference picture index.
  • the motion information may further include inter prediction direction (L0 prediction, L1 prediction, Bi prediction, etc.) information.
  • the neighboring block may include a spatial neighboring block existing in the current picture and a temporal neighboring block existing in the reference picture.
  • the inter prediction unit 260 may construct a motion information candidate list based on neighboring blocks, and derive a motion vector and/or a reference picture index of the current block based on the received candidate selection information.
  • Inter prediction may be performed based on various prediction modes (techniques), and the information about the prediction may include information indicating a mode (technique) of inter prediction for the current block.
  • the addition unit 235 is reconstructed by adding the obtained residual signal to the prediction signal (predicted block, prediction sample array) output from the prediction unit (including the inter prediction unit 260 and/or the intra prediction unit 265). Signals (restored pictures, reconstructed blocks, reconstructed sample arrays) can be generated. The description of the addition unit 155 may be equally applied to the addition unit 235.
  • LMCS luma mapping with chroma scaling
  • the filtering unit 240 may apply filtering to the reconstructed signal to improve subjective/objective image quality.
  • the filtering unit 240 may generate a modified reconstructed picture by applying various filtering methods to the reconstructed picture, and the modified reconstructed picture may be converted to the memory 250, specifically the DPB of the memory 250. Can be saved on.
  • the various filtering methods may include, for example, deblocking filtering, sample adaptive offset, adaptive loop filter, bilateral filter, and the like.
  • the (modified) reconstructed picture stored in the DPB of the memory 250 may be used as a reference picture in the inter prediction unit 260.
  • the memory 250 may store motion information of a block from which motion information in a current picture is derived (or decoded) and/or motion information of blocks in a picture that have already been reconstructed.
  • the stored motion information may be transmitted to the inter prediction unit 260 to be used as motion information of a spatial neighboring block or motion information of a temporal neighboring block.
  • the memory 250 may store reconstructed samples of reconstructed blocks in the current picture, and may be transmitted to the intra prediction unit 265.
  • the embodiments described in the filtering unit 160, the inter prediction unit 180, and the intra prediction unit 185 of the encoding apparatus 100 are, respectively, the filtering unit 240 and the inter prediction unit of the image decoding apparatus 200.
  • the same or corresponding to the prediction unit 260 and the intra prediction unit 265 may be applied.
  • FIG. 4 is a flowchart illustrating a process of generating a prediction block (predicted block) of a current block by performing intra prediction.
  • the process illustrated in FIG. 4 may be performed by the intra prediction unit 185 of FIG. 2 and/or the intra prediction unit 265 of FIG. 3.
  • determination of whether to perform intra prediction of FIG. 4 on the current block may be performed based on rate-distortion optimization (RDO).
  • RDO rate-distortion optimization
  • the prediction mode for the current block may be determined as the intra prediction mode.
  • a method of determining a prediction mode for a current block is not limited to the above example.
  • determination of whether to perform intra prediction of FIG. 4 on the current block may be performed based on information on the prediction mode of the current block.
  • the information on the prediction mode of the current block may be information indicating whether the prediction mode of the current block is an intra prediction mode or an inter prediction mode.
  • Information about the prediction mode of the current block may be explicitly signaled through a bitstream, or may be implicitly derived based on an encoding parameter about the current block.
  • the encoding/decoding method includes determining an intra prediction mode (S410), configuring a reference sample (S420), and/or performing intra prediction (S430). ) Can be included.
  • the image encoding apparatus or the image decoding apparatus may determine a type of at least one intra prediction technique that can be used for intra prediction.
  • an encoding/decoding method that can be used to perform intra prediction is defined as an intra prediction technique.
  • the intra prediction technique may mean one of an encoding/decoding method used to determine an intra prediction mode, an encoding/decoding method used to construct a reference sample, and/or an encoding/decoding method used to derive a prediction sample. have. That is, based on the determined intra prediction technique, at least one of steps S410 to S430 of FIG. 4 may be performed.
  • the intra prediction mode of the current block may be determined as one of a plurality of intra prediction modes including non-directional intra prediction modes and directional intra prediction modes.
  • a prediction sample of the current block may be derived based on an average or interpolation of neighboring reference samples of the current block.
  • a prediction sample of the current block may be derived based on a reference sample existing in a specific (prediction) direction with respect to a prediction target sample among neighboring reference samples of the current block. .
  • the intra prediction mode of the current block may be determined using the intra prediction mode of the neighboring block.
  • the image decoding apparatus may select one of the MPM candidates in the MPM list derived based on the intra prediction mode of the neighboring block of the current block and the additional candidate modes based on the MPM index received from the image encoding apparatus.
  • the neighboring block may include at least one of the left and/or upper neighboring blocks of the current block.
  • the video decoding apparatus may determine one of the intra prediction modes not included in the MPM list as the intra prediction mode of the current block.
  • Whether an intra prediction mode applied to the current block exists in the MPM list may be determined based on an MPM flag (eg, mpm_flag or intra_luma_mpm_flag). For example, when the prediction mode of the current block is included in the MPM list, the MPM flag may have a first value. When the prediction mode of the current block is not included in the MPM list, the prediction mode of the current block may be determined as one of the remaining prediction modes. The remaining prediction mode may mean the remaining intra prediction modes that are not included in the MPM list. When the prediction mode of the current block is not included in the MPM list, the MPM flag may have a second value.
  • an MPM flag eg, mpm_flag or intra_luma_mpm_flag
  • the prediction mode of the current block may be determined by an MPM index (eg, mpm_idx or intra_luma_mpm_idx).
  • the prediction mode of the current block may be determined based on remaining prediction mode information (eg, rem_intra_luma_pred_mode or intra_luma_mpm_remainder).
  • Remaining intra prediction mode information may indicate one of all intra prediction modes by indexing the remaining intra prediction modes not included in the MPM list in the order of prediction mode numbers.
  • the intra prediction mode may be an intra prediction mode for a luma component (sample).
  • the MPM list may be referred to in various terms such as an MPM candidate list and candModeList.
  • the prediction sample of the current block is the intra prediction mode of the current block based on the prediction target sample of the current block among neighboring reference samples. It may be generated through interpolation between a first surrounding sample located in the prediction direction and a second surrounding sample located in the opposite direction.
  • LIP linear interpolation intra prediction
  • chroma prediction samples may be generated based on luma samples using a linear model.
  • a temporary prediction sample of the current block is derived based on the filtered surrounding reference samples, and existing surrounding reference samples, that is, unfiltered surrounding reference
  • a prediction sample of the current block may be derived by weighted summation of at least one reference sample derived according to the intra prediction mode among samples and the temporary prediction sample.
  • the intra prediction technique is multi-reference line intra prediction (MRL) or MRL-based intra prediction
  • a reference sample line with the highest prediction accuracy is selected among neighboring multi-reference sample lines of the current block
  • a prediction sample can be derived using a reference sample located at.
  • information on the used reference sample line eg, intra_luma_ref_idx
  • intra_luma_ref_idx may be encoded in the bitstream and signaled.
  • the intra prediction technique is Intra Sub-Partitions (ISP) or ISP-based intra prediction
  • the current block is divided into vertical or horizontal sub-partitions, and intra prediction mode is used for each sub-partition. You can make predictions.
  • neighboring reference samples of intra prediction may be derived in each sub-partition unit. That is, the reconstructed samples of the previous sub-partition in the encoding/decoding order may be used as neighboring reference samples of the current sub-partition.
  • the intra prediction techniques may be referred to in various terms such as an intra prediction type or an additional intra prediction mode, separated from a directional or non-directional intra prediction mode.
  • a plurality of intra prediction techniques are not limited to the above example, and some intra prediction techniques may be omitted or other intra prediction techniques may be added. For example, if necessary, an intra prediction technique for performing post-processing filtering on the derived prediction samples may be added. Also, a plurality of intra prediction techniques may be used exclusively, or two or more intra prediction techniques may be applied to the current block.
  • the encoding parameter may include a size (width and/or height) of the current block, a color component of the current block, or whether or not other intra prediction techniques are applied.
  • the determination of whether the corresponding intra prediction technique is available for the current block may be performed based on information signaled at a higher level of the current block, such as a sequence, picture, slice, and CTU. For example, when information transmitted at the sequence level indicates that a predetermined intra prediction technique is not available, it may be determined that the corresponding intra prediction technique is not available for blocks belonging to the corresponding sequence.
  • the video encoding apparatus may determine whether the corresponding intra prediction technique is applied to the current block using various methods. For example, the image encoding apparatus may determine whether to apply a corresponding intra prediction technique based on RDO.
  • the video encoding apparatus may encode information on whether or not a corresponding intra prediction technique is applied (hereinafter, referred to as intra prediction technique information) into a bitstream to signal.
  • Intra prediction technique information may be encoded in various forms according to a corresponding intra prediction technique.
  • the intra prediction technique information may be a multiple reference line index (eg, intra_luma_ref_idx) indicating a reference sample line used for prediction of a current block among multiple reference lines.
  • intra_luma_ref_idx may indicate a reference sample line for intra prediction of the current block according to the binary sequence of Table 1 below.
  • Table 1 The binary display of Table 1 is an example of the present disclosure, and the scope of the present disclosure is not limited according to the binary values below.
  • intra prediction for a current block may be performed using a 0th reference sample line of the current block. That is, when the current block is intra-predicted by using the 0-th reference sample line, the video encoding apparatus or the video decoding apparatus may encode/decode 0 as a binary value of intra_luma_ref_idx. Similarly, when the current block is encoded/decoded using the first or third reference sample line, intra_luma_ref_idx may be encoded/decoded with a binary value of 10 or 11, respectively.
  • the intra prediction technique information may be flag information (eg, intra_subpartitions_mode_flag) indicating whether the ISP is applied to the current block.
  • flag information indicating whether the ISP is applied may be a sub-partition intra prediction flag.
  • the intra prediction technique information may additionally include flag information indicating a splitting direction for the ISP (eg, intra_subpartitions_split_flag).
  • flag information indicating the division direction for the ISP may be a sub-partition intra prediction direction flag.
  • a sub-partition intra prediction flag and a sub-partition intra prediction direction flag may be defined as a sub-partition intra prediction syntax. For example, whether or not the ISP is performed and the direction of division of the ISP may be determined according to the binary sequence in Table 2 below. The binary numbers in Table 2 are examples, and the scope of the present disclosure is not limited according to the binary values below.
  • intra_subpartitions_mode_flag when intra_subpartitions_mode_flag has a binary value of 1, a current block may be intra predicted using an ISP. That is, when the current block is encoded/decoded using an ISP, intra_subpartitions_mode_flag may be encoded/decoded with a binary value of 1. On the other hand, when the ISP is not applied to the current block, intra_subpartitions_mode_flag may be encoded/decoded with a binary value of 0.
  • the image encoding apparatus or the image decoding apparatus may encode/decode intra_subpartitions_split_flag.
  • intra_subpartitions_split_flag has a binary value of 0
  • the current block is divided in the horizontal direction, and the ISP may be applied.
  • intra_subpartitions_split_flag has a binary value of 1
  • the current block is divided in the vertical direction, and the ISP can be applied.
  • the intra prediction method information may include flag information indicating whether PDPC is applied, flag information indicating whether LIP is applied, flag information indicating whether the LM mode is applied, and the like.
  • the video decoding apparatus may determine whether to apply the corresponding intra prediction technique to the current block based on the signaled intra prediction technique information.
  • whether to apply a predetermined intra prediction technique to the current block may be implicitly derived from the video encoding apparatus and the video decoding apparatus based on encoding parameters for the current block in addition to the explicitly signaled intra prediction technique information.
  • the encoding parameter may include a size (width and/or height) of the current block, a color component of the current block, or whether or not other intra prediction techniques are applied.
  • a reference sample to be used for intra prediction of the current block may be constructed from neighboring reference samples of the current block.
  • intra prediction of the current block is performed in step S430 to generate a prediction block of the current block.
  • the prediction block (predicted block) of the current block may be added to the residual signal of the current block and used to generate a reconstructed signal of the current block.
  • an image encoding apparatus or an image decoding apparatus may encode/decode an image using an integrated syntax element in which a plurality of syntaxes are merged.
  • the unified syntax element may mean a syntax element in which two or more different single syntaxes are merged.
  • the unified syntax element according to the present disclosure is described as being configured by merging at least one of an MPM flag, a multi-reference line index, and a sub-partition intra prediction syntax. It is not.
  • the present disclosure may include not only the proposed syntax, but also the concept of merging arbitrary syntaxes used for intra prediction into one unified syntax.
  • the unified syntax element may be referred to as a single syntax element or a first syntax element. Due to the nature of terms used in the present disclosure, the scope of the rights of the present disclosure does not change.
  • FIG. 5 is a diagram for describing an image decoding method according to an embodiment of the present disclosure.
  • determining whether a prediction mode of a current block is an intra prediction mode based on information about a prediction mode of a current block S510
  • the prediction mode of the current block is the intra prediction mode
  • parsing a syntax element related to intra prediction of the current block S520
  • uses the parsed syntax element a prediction block for the current block. It may include the step of generating (S530).
  • the syntax element related to intra prediction of the current block may include a first syntax element used to determine an intra prediction setting of at least two different intra prediction techniques.
  • FIG. 6 is a diagram for describing an image encoding method according to an embodiment of the present disclosure.
  • determining whether a prediction mode of a current block is an intra prediction mode (S610), and when a prediction mode of a current block is an intra prediction mode It may include performing intra prediction to generate a prediction block for the current block (S620) and encoding a syntax element related to intra prediction of the current block (S630).
  • the syntax element related to intra prediction of the current block may include a first syntax element used to determine an intra prediction setting of at least two different intra prediction techniques.
  • the first syntax element may include at least one of an MPM flag, a multiple reference line index, and a sub-partition intra prediction syntax. That is, the intra prediction technique according to some embodiments of the present disclosure may include at least one of MPM, MRL, and ISP.
  • the image encoding apparatus or the image decoding apparatus may determine a reference sample line used for prediction. For example, the image encoding apparatus or the image decoding apparatus may encode/decode intra_luma_ref_idx.
  • the video encoding apparatus or video decoding apparatus may determine whether the current block uses the ISP. For example, the image encoding apparatus or the image decoding apparatus may encode/decode intra_subpartitions_mode_flag indicating whether the ISP is performed. When the ISP is applied to the current block, the image encoding apparatus or the image decoding apparatus may determine a splitting direction for the ISP. For example, the image encoding apparatus or the image decoding apparatus may encode/decode intra_subpartitions_mode_flag indicating the division direction of the ISP.
  • intra_subpartitions_mode_flag may be determined according to an MRL condition.
  • the image encoding apparatus or the image decoding apparatus may decode the intra_subpartitions_mode_flag only when the current block is intra predicted using the 0th reference sample line. That is, only when the current block uses the 0th reference sample line, whether or not to use the ISP may be determined.
  • whether to use the ISP for the current block may be implicitly determined. For example, when the current block uses the 1st or 3rd reference sample line, the ISP may not be applied to the current block.
  • the image encoding apparatus or the image decoding apparatus may encode/decode the MPM flag based on the MRL condition and the ISP condition. For example, when the current block uses the 0th reference sample line but does not use the ISP, the image encoding apparatus or the image decoding apparatus may encode/decode the MPM flag.
  • Table 3 shows a syntax binarization table according to a conventional encoding/decoding method. Table 3 shows one binary value encoded/decoded according to each condition, but each binary value may be a result of sequentially encoding/decoding at least one of a multi-reference line index, sub-partition intra prediction syntax, and MPM flag. have.
  • a horizontal ISP, and MPM, 010 or 10 may be sequentially encoded/decoded according to MRL and ISP conditions.
  • FIG. 7 is a diagram for explaining a syntax encoding/decoding method according to a conventional method.
  • intra_luma_ref_idx may be encoded/decoded.
  • intra_luma_ref_idx it may be determined whether the current block is encoded/decoded using which reference sample line (S720).
  • intra_subpartitions_mode_flag may be encoded/decoded (S730).
  • the process may be terminated without encoding/decoding an additional syntax.
  • intra_subpartitions_mode_flag 1
  • intra_subpartitions_split_flag 1
  • intra_subpartitions_split_flag 1
  • whether to perform step S710 may be determined based on whether or not MRL can be applied to the current block.
  • whether MRL can be applied to the current block may be determined based on at least one of a size of a current block, a component, a maximum transform size of a block, a minimum transform size, and a split depth.
  • that MRL is applied may mean that encoding/decoding of the current block is performed through a reference sample line other than reference sample line 0 (eg, reference sample line 1 or 3).
  • whether to perform step S730 may be determined based on whether or not ISP is applicable to the current block. For example, whether the ISP can be applied to the current block may be determined based on at least one of a size of a current block, a component, a maximum transform size of a block, a minimum transform size, and a split depth.
  • FIG. 8 is a diagram illustrating a structure of a bitstream reflecting a syntax encoding/decoding method according to a conventional method.
  • FIG. 8 is a syntax structure for a current block and shows a syntax encoding/decoding method according to a conventional method.
  • intra_luma_ref_idx may be encoded/decoded.
  • whether to perform encoding/decoding for intra_luma_ref_idx may be determined based on the position of the current block.
  • whether to perform encoding/decoding for intra_luma_ref_idx may be determined based on a condition according to Equation 1 below.
  • Equation 1 may be a conditional expression for determining whether MRL can be applied to the current block.
  • Equation 1 may be a condition for determining whether the upper boundary of the current block coincides with the upper boundary of the current coding tree block (CTB). For example, if Equation 1 is satisfied, the upper boundary of the current block does not coincide with the upper boundary of the CTB, and in this case, intra_luma_ref_idx is not transmitted, and its value may be derived as 0.
  • CTB current coding tree block
  • intra_sub_partitions_mode_flag may be encoded/decoded.
  • whether to perform encoding/decoding for intra_sub_partitions_mode_flag may be determined based on at least one of intra_luma_ref_idx, a size of a current block, a component, a maximum transform block size, a minimum transform block size, and a depth of the current block.
  • whether to perform encoding/decoding for intra_sub_partitions_mode_flag may be determined based on a condition according to Equation 2 below.
  • MinTbSizeY may mean a minimum transform size of a block
  • MaxTbSizeY may mean a maximum transform size of a block.
  • Equation 2 may be a conditional expression for determining whether to apply the ISP to the current block.
  • cbHeight ⁇ MaxTbSizeY) && (cbWidth Y* cbHeight> MinTbSizeY * )
  • intra_subpartions_split_flag may be encoded/decoded.
  • whether to perform encoding/decoding on the intra_subpartions_split_flag may be determined based on at least one of intra_subpartitions_mode_flag, the size of the current block, the maximum transform block size, the minimum transform block size, and the depth of the current block.
  • whether to perform encoding/decoding for intra_subpartions_split_flag may be determined based on a condition according to Equation 3 below.
  • intra_luma_mpm_flag may be encoded/decoded.
  • whether to perform encoding/decoding for intra_luma_mpm_flag may be determined based on at least one of intra_luma_ref_idx and intra_sub_partitions_mode_flag.
  • whether to perform encoding/decoding for intra_luma_mpm_flag may be determined based on a condition according to Equation 4 below.
  • the integrated syntax Provides a way to assign binary values to elements.
  • a conventional multiple reference line index, a sub-partition intra prediction flag, and an MPM flag may be merged through an unified syntax element.
  • an integrated syntax element according to the present disclosure may be named intra_syntax_idx.
  • FIG. 9 is another diagram for describing an image encoding/decoding method according to an embodiment of the present disclosure.
  • an image encoding apparatus or an image decoding apparatus may encode/decode an integrated syntax element intra_syntax_idx (S910).
  • an intra prediction setting of an intra prediction technique for intra prediction of a current block may be determined according to an intra_syntax_idx and an MRL and an ISP applicable condition (S920).
  • Table 4 shows an example of applying the unified syntax element to the syntax binarization table of Table 3.
  • the multi-reference line index, the sub-partition intra prediction syntax, and the MPM flag may be merged into an integrated syntax element intra_syntax_idx to be encoded/decoded, and the binary value of the encoded/decoded intra_syntax_idx may vary according to the MRL and ISP application conditions.
  • Table 3 shows binary values in which a plurality of different syntaxes are sequentially encoded/decoded, while Table 4 shows binary values that one integrated syntax element can have for each condition.
  • the image encoding apparatus or the image decoding apparatus may encode/decode intra_syntax_idx using the same binarization table as the conventional syntax binarization table.
  • whether or not MPM is applied to the current block may be determined according to whether intra_syntax_idx is 0.
  • the binary value allocated to the integrated syntax element may be determined according to at least one of an MRL applicable condition and an ISP applicable condition.
  • MRL and ISP may not be applied to the current block.
  • the binary value allocated to the integrated syntax element may be determined according to at least one of an MRL applicable condition and an ISP applicable condition.
  • whether the ISP is applied to the current block may be determined according to whether the intra_syntax_idx is 2 or 3. For example, when intra_syntax_idx is 2 or 3, the ISP may be applied to the current block. Meanwhile, when intra_syntax_idx is 2, the ISP division direction of the current block may be determined in the horizontal (or vertical) direction. On the other hand, when intra_syntax_idx is 3, the ISP division direction of the current block may be determined in a vertical (or horizontal) direction. In this case, the binary value allocated to the unified syntax element may be determined according to the MRL applicable condition.
  • whether or not MRL is applied to the current block may be determined according to whether the intra_syntax_idx is 4 or 5. For example, when intra_syntax_idx is 4 or 5, MRL may be applied to the current block. Meanwhile, when the intra_syntax_idx is 4, the reference sample line index of the current block may be determined as the 1st (or 3rd) reference sample line. On the other hand, when intra_syntax_idx is 5, the reference sample line index of the current block may be determined as the 3rd (or 1st) reference sample line. In this case, the binary value allocated to the integrated syntax element may be determined according to an ISP applicable condition.
  • the intra_syntax_idx and binary value allocation in Table 4 is an example, and the scope of the present disclosure is not limited according to the above-described syntax element and binary value allocation combination embodiment.
  • the video encoding device or video decoding device can set the encoding/decoding priority of the MPM flag high.
  • Table 5 shows a syntax binarization table in which priority is assigned to the MPM flag. A detailed method for determining the setting of the intra prediction scheme based on Table 5 is the same as described through Table 4, and thus a description thereof will be omitted.
  • the image encoding apparatus or the image decoding apparatus may change the priority of bit (binary value) allocation when encoding/decoding an integrated syntax element.
  • the video encoding apparatus or video decoding apparatus may give a high priority to setting an intra prediction technique with a high frequency of occurrence, and add a low priority to setting an intra prediction technique with a low frequency of occurrence.
  • a high priority may be applied to the allocation of a binary value to an MPM flag. That is, a binary value having a small number of digits may be allocated to the MPM flag merged into the unified syntax.
  • a low priority may be applied to the multiple reference line index and the sub-partition intra prediction syntax. That is, when the MRL and ISP are applied, a binary value having a large number of digits may be allocated to the reference line index and sub-partition intra prediction syntax merged into the unified syntax.
  • a binary value of 1 or 2 digits may be allocated to the unified syntax element.
  • the syntax binarization table of Table 6 below may be an example of improving the syntax binarization table of Table 5.
  • At least two or more of a multiple reference line index, a sub-partition intra prediction syntax, and an MPM flag may be merged into intra_syntax_idx to be encoded/decoded. That is, only some of the multi-reference line index, the sub-partition intra prediction syntax, and the MPM flag may be merged into an integrated syntax element to be encoded/decoded.
  • FIG. 10 is a diagram for describing an image encoding/decoding method according to another embodiment of the present disclosure.
  • the multi-reference line index and the sub-partition intra prediction syntax excluding the MPM flag may be merged into the integrated syntax element intra_syntax_idx to be encoded/decoded.
  • Table 7 below shows a syntax binarization table according to the present embodiment.
  • the MPM flag is encoded/decoded separately from the unified syntax element
  • the priority between the MRL and the ISP can be arbitrarily determined.
  • FIG. 11 is a diagram illustrating a structure of a bitstream reflecting a syntax encoding/decoding method according to another embodiment of the present disclosure.
  • 11 is a syntax structure for a current block and shows an encoding/decoding method using an MPM flag and an integrated syntax element.
  • intra_luma_mpm_flag may be encoded/decoded.
  • whether to perform encoding/decoding for intra_luma_mpm_flag may be determined according to split tree information for the current block. For example, when the current block is a block belonging to a single tree or a luminance dual tree, encoding/decoding for intra_luma_mpm_flag may be performed.
  • intra_syntax_idx may be encoded/decoded. Specifically, when intra_luma_mpm_flag has a value of 1, intra_syntax_idx may be encoded/decoded. That is, only when MPM is applied to the current block, intra_syntax_idx may be encoded/decoded. Since the encoding/decoding for intra_luma_mpm_idx and intra_luma_mpm_remainder is the same as the MPM operation described above, a description thereof will be omitted.
  • the MPM flag is excluded from merging of the unified syntax element, but the scope of the present disclosure is not limited to this embodiment.
  • one of the reference sample line index and the sub-partition intra prediction syntax may be excluded from merging of the unified syntax element.
  • syntax elements related to intra prediction that have been sequentially encoded/decoded in the related art can be encoded/decoded with one integrated syntax, so that encoding/decoding efficiency can be improved. Also, according to embodiments of the present disclosure, by preferentially encoding/decoding syntax elements related to prediction with a high frequency of occurrence, encoding/decoding efficiency may be improved.
  • exemplary methods of the present disclosure are expressed as a series of operations for clarity of description, but this is not intended to limit the order in which steps are performed, and each step may be performed simultaneously or in a different order if necessary.
  • the illustrative steps may include additional steps, other steps may be included excluding some steps, or may include additional other steps excluding some steps.
  • an image encoding apparatus or an image decoding apparatus performing a predetermined operation may perform an operation (step) of confirming an execution condition or situation of the operation (step). For example, when it is described that a predetermined operation is performed when a predetermined condition is satisfied, the video encoding apparatus or the video decoding apparatus performs an operation to check whether the predetermined condition is satisfied, and then performs the predetermined operation. I can.
  • various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof.
  • one or more ASICs Application Specific Integrated Circuits
  • DSPs Digital Signal Processors
  • DSPDs Digital Signal Processing Devices
  • PLDs Programmable Logic Devices
  • FPGAs Field Programmable Gate Arrays
  • general purpose It may be implemented by a processor (general processor), a controller, a microcontroller, a microprocessor, or the like.
  • the image decoding device and the image encoding device to which the embodiment of the present disclosure is applied include a multimedia broadcasting transmission/reception device, a mobile communication terminal, a home cinema video device, a digital cinema video device, a surveillance camera, a video chat device, and a real-time communication device such as video communication.
  • Mobile streaming devices storage media, camcorders, video-on-demand (VoD) service providers, OTT video (Over the top video) devices, Internet streaming service providers, three-dimensional (3D) video devices, video telephony video devices, and medical use. It may be included in a video device or the like, and may be used to process a video signal or a data signal.
  • an OTT video (Over the top video) device may include a game console, a Blu-ray player, an Internet-connected TV, a home theater system, a smartphone, a tablet PC, and a digital video recorder (DVR).
  • DVR digital video recorder
  • FIG. 12 is a diagram illustrating a content streaming system to which an embodiment of the present disclosure can be applied.
  • the content streaming system to which the embodiment of the present disclosure is applied may largely include an encoding server, a streaming server, a web server, a media storage device, a user device, and a multimedia input device.
  • the encoding server serves to generate a bitstream by compressing content input from multimedia input devices such as smartphones, cameras, camcorders, etc. into digital data, and transmits it to the streaming server.
  • multimedia input devices such as smartphones, cameras, camcorders, etc. directly generate bitstreams
  • the encoding server may be omitted.
  • the bitstream may be generated by an image encoding method and/or an image encoding apparatus to which an embodiment of the present disclosure is applied, and the streaming server may temporarily store the bitstream in a process of transmitting or receiving the bitstream.
  • the streaming server may transmit multimedia data to a user device based on a user request through a web server, and the web server may serve as an intermediary informing the user of a service.
  • the web server transmits the request to the streaming server, and the streaming server may transmit multimedia data to the user.
  • the content streaming system may include a separate control server, and in this case, the control server may play a role of controlling a command/response between devices in the content streaming system.
  • the streaming server may receive content from a media storage and/or encoding server. For example, when content is received from the encoding server, the content may be received in real time. In this case, in order to provide a smooth streaming service, the streaming server may store the bitstream for a predetermined time.
  • Examples of the user device include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a slate PC, and Tablet PC, ultrabook, wearable device, for example, smartwatch, smart glass, head mounted display (HMD)), digital TV, desktop There may be computers, digital signage, etc.
  • PDA personal digital assistant
  • PMP portable multimedia player
  • HMD head mounted display
  • TV desktop
  • desktop There may be computers, digital signage, etc.
  • Each server in the content streaming system may be operated as a distributed server, and in this case, data received from each server may be distributedly processed.
  • the scope of the present disclosure is software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause an operation according to the method of various embodiments to be executed on a device or computer, and such software or It includes a non-transitory computer-readable medium (non-transitory computer-readable medium) which stores instructions and the like and is executable on a device or a computer.
  • a non-transitory computer-readable medium non-transitory computer-readable medium
  • An embodiment according to the present disclosure may be used to encode/decode an image.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)

Abstract

L'invention concerne un procédé et un appareil de codage/décodage de vidéo. Un procédé de décodage de vidéo, selon la présente invention, est un procédé de décodage de vidéo exécuté par un appareil de décodage de vidéo, le procédé de décodage de vidéo comprenant les étapes consistant à : déterminer, sur la base d'informations sur un mode de prédiction d'un bloc courant, si le mode de prédiction du bloc courant est un mode de prédiction intra ; analyser, lorsque le mode de prédiction du bloc courant est le mode de prédiction intra, un élément de syntaxe lié à la prédiction intra du bloc courant ; et générer un bloc de prédiction pour le bloc courant à l'aide de l'élément de syntaxe analysé, l'élément de syntaxe relatif à la prédiction intra du bloc courant pouvant comprendre un premier élément de syntaxe utilisé pour déterminer des paramètres de prédiction intra d'au moins deux techniques de prédiction intra différentes.
PCT/KR2020/003128 2019-03-06 2020-03-05 Procédé et appareil de codage/décodage de vidéo et procédé de transmission de flux binaire Ceased WO2020180133A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201962814854P 2019-03-06 2019-03-06
US62/814,854 2019-03-06

Publications (1)

Publication Number Publication Date
WO2020180133A1 true WO2020180133A1 (fr) 2020-09-10

Family

ID=72337939

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2020/003128 Ceased WO2020180133A1 (fr) 2019-03-06 2020-03-05 Procédé et appareil de codage/décodage de vidéo et procédé de transmission de flux binaire

Country Status (1)

Country Link
WO (1) WO2020180133A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150071003A (ko) * 2015-06-05 2015-06-25 에스케이텔레콤 주식회사 영상 부호화/복호화 방법 및 장치
KR20180009318A (ko) * 2016-07-18 2018-01-26 한국전자통신연구원 영상 부호화/복호화 방법, 장치 및 비트스트림을 저장한 기록 매체
KR20180015598A (ko) * 2016-08-03 2018-02-13 주식회사 케이티 비디오 신호 처리 방법 및 장치
WO2018205950A1 (fr) * 2017-05-09 2018-11-15 Huawei Technologies Co., Ltd. Intra-prédiction avec de multiples lignes de référence
KR20180123674A (ko) * 2016-04-06 2018-11-19 주식회사 케이티 비디오 신호 처리 방법 및 장치

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20150071003A (ko) * 2015-06-05 2015-06-25 에스케이텔레콤 주식회사 영상 부호화/복호화 방법 및 장치
KR20180123674A (ko) * 2016-04-06 2018-11-19 주식회사 케이티 비디오 신호 처리 방법 및 장치
KR20180009318A (ko) * 2016-07-18 2018-01-26 한국전자통신연구원 영상 부호화/복호화 방법, 장치 및 비트스트림을 저장한 기록 매체
KR20180015598A (ko) * 2016-08-03 2018-02-13 주식회사 케이티 비디오 신호 처리 방법 및 장치
WO2018205950A1 (fr) * 2017-05-09 2018-11-15 Huawei Technologies Co., Ltd. Intra-prédiction avec de multiples lignes de référence

Similar Documents

Publication Publication Date Title
WO2019190181A1 (fr) Procédé de codage d'image/de vidéo basé sur l'inter-prédiction et dispositif associé
WO2020184991A1 (fr) Procédé et appareil de codage/décodage vidéo utilisant un mode ibc, et procédé de transmission de flux binaire
WO2020141879A1 (fr) Procédé et dispositif de décodage de vidéo basé sur une prédiction de mouvement affine au moyen d'un candidat de fusion temporelle basé sur un sous-bloc dans un système de codage de vidéo
WO2021029744A1 (fr) Procédé et appareil de codage/décodage d'image pour déterminer un mode de prédiction d'un bloc de chrominance en se référant à la position d'échantillon de luminance, et procédé de transmission de train de bits
WO2021015537A1 (fr) Procédé et dispositif de codage/décodage d'image permettant de signaler des informations de prédiction de composante de chrominance en fonction de l'applicabilité d'un mode palette et procédé de transmission de flux binaire
WO2020171632A1 (fr) Procédé et dispositif de prédiction intra fondée sur une liste mpm
WO2020231238A1 (fr) Procédé et dispositif de codage/décodage d'image permettant de signaler des informations de filtre sur la base d'un format de chrominance, et procédé de transmission de flux binaire
WO2021137597A1 (fr) Procédé et dispositif de décodage d'image utilisant un paramètre de dpb pour un ols
WO2021040402A1 (fr) Codage d'image ou de vidéo basé sur un codage de palette
WO2020167097A1 (fr) Obtention du type de prédiction inter pour prédiction inter dans un système de codage d'images
WO2020141831A2 (fr) Procédé et appareil de codage d'image faisant appel à une prédiction de copie intra-bloc
WO2020184966A1 (fr) Procédé et dispositif de codage/décodage d'image, et procédé permettant de transmettre un flux binaire
WO2021091252A1 (fr) Procédé et dispositif de traitement d'informations d'image pour codage d'image/vidéo
WO2021040398A1 (fr) Codage d'image ou de vidéo s'appuyant sur un codage d'échappement de palette
WO2020197243A1 (fr) Procédé et dispositif de codage/décodage d'image utilisant une différence de vecteur de mouvement symétrique (smvd) et procédé de transmission de flux binaire
WO2020071832A1 (fr) Procédé de codage de coefficient de transformation et dispositif associé
WO2020256506A1 (fr) Procédé et appareil de codage/décodage vidéo utilisant une prédiction intra à multiples lignes de référence, et procédé de transmission d'un flux binaire
WO2021201617A1 (fr) Appareil et procédé de codage/décodage d'image d'après des informations de sous-image alignées entre des couches, et support d'enregistrement stockant un flux binaire
WO2021107622A1 (fr) Procédé et appareil de codage d'image/de vidéo
WO2020180159A1 (fr) Procédé et appareil de codage/décodage d'images et procédé de transmission d'un flux binaire
WO2020180043A1 (fr) Procédé de codage d'image basé sur le lmcs et dispositif associé
WO2021091256A1 (fr) Procédé et dispositif de codade d'image/vidéo
WO2021015513A1 (fr) Procédé et dispositif de codage/décodage d'image à l'aide d'un filtrage, et procédé de transmission de flux binaire
WO2021091214A1 (fr) Procédé et dispositif de décodage vidéo permettant de coder des informations relatives à un décalage de paramètre de quantification de chrominance
WO2020197222A1 (fr) Procédé et appareil de codage/décodage de signal résiduel faisant appel à des sous-partitions intra (isp), et procédé de transmission de flux binaire

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20766105

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20766105

Country of ref document: EP

Kind code of ref document: A1