WO2020050685A1 - 인트라 예측을 이용한 영상 부호화/복호화 방법 및 장치 - Google Patents

인트라 예측을 이용한 영상 부호화/복호화 방법 및 장치 Download PDF

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WO2020050685A1
WO2020050685A1 PCT/KR2019/011556 KR2019011556W WO2020050685A1 WO 2020050685 A1 WO2020050685 A1 WO 2020050685A1 KR 2019011556 W KR2019011556 W KR 2019011556W WO 2020050685 A1 WO2020050685 A1 WO 2020050685A1
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block
mode
prediction
current block
pixel
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French (fr)
Korean (ko)
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김기백
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Priority to CN202410888486.0A priority Critical patent/CN118612425A/zh
Priority to MYPI2021000976A priority patent/MY207996A/en
Priority to CN202411273878.2A priority patent/CN118945320A/zh
Priority to CN201980058354.2A priority patent/CN112740675B/zh
Priority to CN202410888659.9A priority patent/CN118646869A/zh
Priority to CN202411273989.3A priority patent/CN118972558A/zh
Priority to CN202411273789.8A priority patent/CN118945319A/zh
Priority to CN202410888519.1A priority patent/CN118646868A/zh
Priority to JP2021537422A priority patent/JP2021536717A/ja
Priority to US17/273,848 priority patent/US11917195B2/en
Priority to AU2019336894A priority patent/AU2019336894A1/en
Priority to CN202411273844.3A priority patent/CN119011820A/zh
Priority to CN202411273919.8A priority patent/CN118945321A/zh
Priority to CA3112916A priority patent/CA3112916A1/en
Priority to EP19857599.5A priority patent/EP3849183A4/en
Priority to SG11202101876RA priority patent/SG11202101876RA/en
Publication of WO2020050685A1 publication Critical patent/WO2020050685A1/ko
Priority to PH12021550487A priority patent/PH12021550487A1/en
Priority to ZA2021/01431A priority patent/ZA202101431B/en
Anticipated expiration legal-status Critical
Priority to ZA2022/02999A priority patent/ZA202202999B/en
Priority to US18/526,377 priority patent/US12184894B2/en
Priority to JP2024010892A priority patent/JP7696463B2/ja
Priority to US18/754,945 priority patent/US12382096B2/en
Priority to US18/754,981 priority patent/US20240348824A1/en
Priority to US18/754,969 priority patent/US12610080B2/en
Priority to US19/058,341 priority patent/US20250193441A1/en
Priority to AU2025202197A priority patent/AU2025202197A1/en
Priority to AU2025202196A priority patent/AU2025202196A1/en
Priority to AU2025202199A priority patent/AU2025202199A1/en
Priority to AU2025202195A priority patent/AU2025202195A1/en
Priority to AU2025202193A priority patent/AU2025202193A1/en
Priority to JP2025091078A priority patent/JP2025124790A/ja
Priority to AU2025205194A priority patent/AU2025205194A1/en
Priority to JP2025245480A priority patent/JP2026041997A/ja
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    • 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
    • H04N19/105—Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
    • 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
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    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
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    • 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
    • H04N19/119—Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
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    • 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
    • H04N19/12—Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
    • H04N19/122—Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
    • 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
    • H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
    • H04N19/157—Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
    • H04N19/159—Prediction type, e.g. intra-frame, inter-frame or bidirectional frame prediction
    • 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
    • H04N19/17—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 an image region, e.g. an object
    • H04N19/176—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 an image region, e.g. an object the region being a block, e.g. a macroblock
    • H—ELECTRICITY
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    • 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
    • H04N19/182—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 pixel
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    • 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
    • H04N19/186—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 colour or a chrominance component
    • 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
    • H04N19/46—Embedding additional information in the video signal during the compression process
    • 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 invention relates to an image encoding / decoding method and apparatus.
  • Inter prediction technology that predicts pixel values included in the current picture from pictures before or after the current picture by image compression technology
  • intra prediction technology that predicts pixel values included in the current picture using pixel information in the current picture
  • frequency of appearance Various techniques exist, such as entropy encoding technique in which a short code is assigned to a high value and a long code is assigned to a value having a low frequency of occurrence, and image data can be effectively compressed and transmitted or stored using this image compression technique.
  • An object of the present invention is to provide an intra prediction mode derivation method and apparatus.
  • An object of the present invention is to provide an intra prediction method and apparatus according to component types.
  • An object of the present invention is to provide a block segmentation method and apparatus for intra prediction.
  • the video encoding / decoding method and apparatus of the present invention determines a reference region for intra prediction of a current block, derives an intra prediction mode of the current block based on a predetermined MPM candidate group, and the reference region and the intra Based on the prediction mode, intra prediction may be performed on the current block.
  • the MPM candidate group is divided into a first group and a second group, and the first group includes a default mode predefined in the decoding apparatus, and the second group May include an intra prediction mode of a neighboring block adjacent to the current block.
  • the intra prediction mode of the current block may be derived by selectively using either the first group or the second group.
  • the determining of the reference area may include selecting one pixel line from among a plurality of pixel lines predefined in the decoding apparatus and selecting the selected pixel line. And determining the reference area.
  • the pre-defined plurality of pixel lines include a first pixel line adjacent to the current block, a second pixel line adjacent to the first pixel line, and the second A third pixel line adjacent to the pixel line or a fourth pixel line adjacent to the third pixel line may be included.
  • the default mode is composed of only a non-directional mode, and the non-directional mode may include at least one of a planar mode or a DC mode.
  • the second group further includes a mode derived by adding or subtracting an N value to the intra prediction mode of the neighboring block, wherein the N value is 1, 2, or It can be 3.
  • the video encoding / decoding method and apparatus of the present invention may obtain a first flag from a bitstream, and the first flag may indicate whether an intra prediction mode of the current block is derived from the first group. .
  • the intra prediction mode of the current block is set to MPM belonging to the first group, and the value of the first flag If this is the second value, the intra prediction mode of the current block can be derived based on the second group and the MPM index.
  • the first flag may be signaled only when the reference area of the current block is the first pixel line.
  • the video encoding / decoding method and apparatus of the present invention may determine an intra prediction mode of a current block and perform intra prediction on a current block based on the determined intra prediction mode.
  • the intra prediction mode of the current block may be derived for a luminance block and a color difference block, respectively.
  • an intra prediction mode of a luminance block is derived based on an MPM list and an MPM index, and the MPM list is an intra prediction mode (ModeA) of a neighboring block (ModeA + n) , (ModeA-n), or at least one of a deflated mode.
  • the video encoding / decoding method and apparatus of the present invention specify a luminance region for reference between components of a color difference block, perform downsampling on the luminance region, derive parameters for reference between components of the color difference block, ,
  • the chrominance block may be predicted based on the downsampled luminance block and the parameter.
  • the current block is divided into a plurality of sub-blocks, and the division may be performed based on at least one of the size or shape of the current block.
  • prediction can be performed more accurately and efficiently by deriving intra prediction modes based on MPM candidate groups.
  • the present invention can improve the efficiency of intra prediction encoding / decoding through adaptive block division.
  • FIG. 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
  • FIG. 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
  • FIG. 3 illustrates a block division type according to an embodiment to which the present invention is applied.
  • FIG. 4 is a diagram illustrating a tree structure based block partitioning method according to an embodiment to which the present invention is applied.
  • FIG. 5 is an exemplary diagram illustrating an intra-prediction mode pre-defined in an image encoding / decoding apparatus.
  • FIG 6 shows an intra prediction method as an embodiment to which the present invention is applied.
  • FIG 7 is an embodiment to which the present invention is applied, and shows an intra prediction method in sub-block units.
  • FIG. 8 is an embodiment to which the present invention is applied, and illustrates a method for predicting a reference based on components.
  • 9 to 12 is an embodiment to which the present invention is applied, and shows a method of determining a prediction method based on prediction method selection information.
  • the video encoding / decoding method and apparatus of the present invention determines a reference region for intra prediction of a current block, derives an intra prediction mode of the current block based on a predetermined MPM candidate group, and the reference region and the intra Based on the prediction mode, intra prediction may be performed on the current block.
  • the MPM candidate group is divided into a first group and a second group, and the first group includes a default mode predefined in the decoding apparatus, and the second group May include an intra prediction mode of a neighboring block adjacent to the current block.
  • the intra prediction mode of the current block may be derived by selectively using either the first group or the second group.
  • the determining of the reference area may include selecting one pixel line from among a plurality of pixel lines predefined in the decoding apparatus and selecting the selected pixel line. And determining the reference area.
  • the pre-defined plurality of pixel lines include a first pixel line adjacent to the current block, a second pixel line adjacent to the first pixel line, and the second A third pixel line adjacent to the pixel line or a fourth pixel line adjacent to the third pixel line may be included.
  • the default mode is composed of only a non-directional mode, and the non-directional mode may include at least one of a planar mode or a DC mode.
  • the second group further includes a mode derived by adding or subtracting an N value to the intra prediction mode of the neighboring block, wherein the N value is 1, 2, or It can be 3.
  • the video encoding / decoding method and apparatus of the present invention may obtain a first flag from a bitstream, and the first flag may indicate whether an intra prediction mode of the current block is derived from the first group. .
  • the intra prediction mode of the current block is set to MPM belonging to the first group, and the value of the first flag If this is the second value, the intra prediction mode of the current block can be derived based on the second group and the MPM index.
  • the first flag may be signaled only when the reference area of the current block is the first pixel line.
  • the video encoding / decoding method and apparatus of the present invention may determine an intra prediction mode of a current block and perform intra prediction on a current block based on the determined intra prediction mode.
  • the intra prediction mode of the current block may be derived for a luminance block and a color difference block, respectively.
  • an intra prediction mode of a luminance block is derived based on an MPM list and an MPM index, and the MPM list is an intra prediction mode (ModeA) of a neighboring block (ModeA + n) , (ModeA-n), or at least one of a deflated mode.
  • the video encoding / decoding method and apparatus of the present invention specify a luminance region for reference between components of a color difference block, perform downsampling on the luminance region, derive parameters for reference between components of the color difference block, ,
  • the chrominance block may be predicted based on the downsampled luminance block and the parameter.
  • the current block is divided into a plurality of sub-blocks, and the division may be performed based on at least one of the size or shape of the current block.
  • first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components.
  • first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component.
  • FIG. 1 is a block diagram showing an image encoding apparatus according to an embodiment of the present invention.
  • the image encoding apparatus 100 includes a picture splitter 110, a prediction unit 120, 125, a transform unit 130, a quantization unit 135, a reordering unit 160, and an entropy coding unit ( 165), an inverse quantization unit 140, an inverse conversion unit 145, a filter unit 150 and a memory 155.
  • each component shown in FIG. 1 is independently illustrated to represent different characteristic functions in the image encoding apparatus, and does not mean that each component is composed of separate hardware or a single software component.
  • each component is included in each component unit for convenience of description, and at least two of the components may be combined into one component, or one component may be divided into a plurality of components to perform a function.
  • Integrated and separate embodiments of the components are also included within the scope of the present invention without departing from the spirit of the invention.
  • the components are not essential components for performing essential functions in the present invention, but may be optional components for improving performance.
  • the present invention can be implemented by including only components necessary for realizing the essence of the present invention, except for components used for performance improvement, and structures including only essential components excluding optional components used for performance improvement. Also included in the scope of the present invention.
  • the picture division unit 110 may divide the input picture into at least one processing unit.
  • the processing unit may be a prediction unit (PU), a transformation unit (TU), or a coding unit (CU).
  • the picture division unit 110 divides a single picture into a combination of a plurality of coding units, prediction units, and transformation units, and combines one coding unit, prediction unit, and transformation unit with a predetermined criterion (for example, a cost function). You can code a picture by selecting.
  • a predetermined criterion for example, a cost function
  • one picture may be divided into a plurality of coding units.
  • a recursive tree structure such as a quad tree structure can be used.
  • One image or a coding that is split into another coding unit using a largest coding unit as a root The unit may be divided into as many child nodes as the number of divided coding units.
  • a coding unit that is no longer split is a leaf node. That is, when it is assumed that only square division is possible for one coding unit, one coding unit may be divided into up to four different coding units.
  • a coding unit may be used as a unit for encoding or as a unit for decoding.
  • the prediction unit may be divided into at least one square or rectangular shape having the same size within one coding unit, and one prediction unit among the prediction units split within one coding unit may be another prediction unit. It may be divided into units having different shapes and / or sizes.
  • intra prediction may be performed without splitting into a plurality of prediction units NxN.
  • the predictors 120 and 125 may include an inter predictor 120 that performs inter prediction and an intra predictor 125 that performs intra prediction. It is determined whether to use inter prediction or intra prediction for a prediction unit, and specific information (eg, intra prediction mode, motion vector, reference picture, etc.) according to each prediction method may be determined. In this case, the processing unit in which the prediction is performed may differ from the processing unit in which the prediction method and the detailed content are determined. For example, the method of prediction and the prediction mode may be determined in the prediction unit, and the prediction may be performed in the transform unit. The residual value (residual block) between the generated prediction block and the original block may be input to the transformer 130.
  • specific information eg, intra prediction mode, motion vector, reference picture, etc.
  • prediction mode information, motion vector information, and the like used for prediction may be encoded by the entropy encoding unit 165 together with the residual value and transmitted to the decoder.
  • the original block may be encoded as it is and transmitted to the decoder without generating the prediction block through the prediction units 120 and 125.
  • the inter prediction unit 120 may predict the prediction unit based on the information of at least one of the previous picture or the next picture of the current picture. In some cases, the inter prediction unit 120 may predict the prediction unit based on the information of the partial region in which the current picture is encoded. You can also predict units.
  • the inter prediction unit 120 may include a reference picture interpolation unit, a motion prediction unit, and a motion compensation unit.
  • the reference picture interpolation unit may receive reference picture information from the memory 155 and generate pixel information of an integer pixel or less in the reference picture.
  • a DCT-based 8-tap interpolation filter having different filter coefficients may be used to generate pixel information of integer pixels or less in units of 1/4 pixels.
  • a DCT-based interpolation filter having different filter coefficients may be used to generate pixel information of an integer pixel or less in units of 1/8 pixels.
  • the motion prediction unit may perform motion prediction based on the reference picture interpolated by the reference picture interpolation unit.
  • various methods such as Full Search-based Block Matching Algorithm (FBMA), Three Step Search (TSS), and New Three-Step Search Algorithm (NTS) can be used.
  • the motion vector may have a motion vector value in units of 1/2 or 1/4 pixels based on the interpolated pixels.
  • the motion prediction unit may predict a current prediction unit by differently using a motion prediction method.
  • Various methods such as a skip method, a merge method, an advanced motion vector prediction (AMVP) method, and an intra block copy method may be used as a motion prediction method.
  • AMVP advanced motion vector prediction
  • the intra prediction unit 125 may generate a prediction unit based on reference pixel information around a current block, which is pixel information in a current picture. If the neighboring block of the current prediction unit is a block that has undergone inter prediction, and the reference pixel is a pixel that has undergone inter prediction, the reference pixel included in the block that has undergone inter prediction is a reference pixel of the block that has undergone intra prediction. It can be used as a substitute for information. That is, when the reference pixel is not available, the available reference pixel information may be replaced with at least one reference pixel among the available reference pixels.
  • the prediction mode may have a directional prediction mode that uses reference pixel information according to a prediction direction and a non-directional mode that does not use directional information when performing prediction.
  • the mode for predicting the luminance information and the mode for predicting the color difference information may be different, and the intra prediction mode information or the predicted luminance signal information used for predicting the luminance information may be utilized to predict the color difference information.
  • intra prediction when performing the intra prediction, if the size of the prediction unit and the size of the transformation unit are the same, intra prediction for the prediction unit based on the pixel located on the left of the prediction unit, the pixel on the top left, and the pixel on the top of the prediction unit You can do
  • intra prediction may be performed using a reference pixel based on the transformation unit.
  • intra prediction using N x N splitting may be used only for a minimum coding unit.
  • the intra prediction method may generate a prediction block after applying an adaptive intra smoothing (AIS) filter to a reference pixel according to a prediction mode.
  • AIS adaptive intra smoothing
  • the type of AIS filter applied to the reference pixel may be different.
  • the intra prediction mode of the current prediction unit may be predicted from the intra prediction mode of the prediction unit existing around the current prediction unit.
  • the prediction mode of the current prediction unit is predicted by using the mode information predicted from the neighboring prediction unit, if the intra prediction mode of the current prediction unit and the neighboring prediction unit is the same, the current prediction unit and the neighboring prediction unit using the predetermined flag information If the prediction modes of the current prediction unit and the neighboring prediction unit are different, the information may be transmitted.
  • Entropy encoding may be performed to encode the prediction mode information of the current block.
  • a residual block may include a prediction unit performing prediction based on the prediction units generated by the prediction units 120 and 125 and residual information including residual information that is a difference from an original block of the prediction unit.
  • the generated residual block may be input to the converter 130.
  • the transformation unit 130 includes a residual block including residual information of a prediction unit generated by the original block and the prediction units 120 and 125, DCT (Discrete Cosine Transform), DST (Discrete Sine Transform), and KLT. It can be converted using the same conversion method. Whether DCT, DST, or KLT is applied to transform the residual block may be determined based on intra prediction mode information of a prediction unit used to generate the residual block.
  • DCT Discrete Cosine Transform
  • DST Discrete Sine Transform
  • KLT Discrete Sine Transform
  • the quantization unit 135 may quantize the values converted by the transformer 130 into the frequency domain.
  • the quantization coefficient may change depending on the block or the importance of the image.
  • the value calculated by the quantization unit 135 may be provided to the inverse quantization unit 140 and the reordering unit 160.
  • the reordering unit 160 may reorder coefficient values with respect to the quantized residual value.
  • the reordering unit 160 may change the two-dimensional block shape coefficient into a one-dimensional vector form through a coefficient scanning method.
  • the rearrangement unit 160 may scan a DC coefficient to a coefficient in a high-frequency region using a Zig-Zag Scan method and change it into a one-dimensional vector form.
  • a vertical scan in which two-dimensional block shape coefficients are scanned in a column direction and a horizontal scan in which two-dimensional block shape coefficients are scanned in a row direction may be used instead of a zig-zag scan. That is, depending on the size of the transform unit and the intra prediction mode, it is possible to determine whether a scan method is used among a zigzag scan, a vertical scan, and a horizontal scan.
  • the entropy encoder 165 may perform entropy encoding based on the values calculated by the reordering unit 160. Entropy encoding may use various encoding methods, such as exponential Golomb, CAVLC (Context-Adaptive Variable Length Coding), and CABAC (Context-Adaptive Binary Arithmetic Coding).
  • the entropy encoding unit 165 includes residual value coefficient information and block type information, prediction mode information, split unit information, prediction unit information, and transmission unit information, motion of the coding unit from the reordering unit 160 and the prediction units 120 and 125.
  • Various information such as vector information, reference frame information, block interpolation information, and filtering information can be encoded.
  • the entropy encoder 165 may entropy encode a coefficient value of a coding unit input from the reordering unit 160.
  • the inverse quantizer 140 and the inverse transformer 145 inverse quantize the quantized values in the quantizer 135 and inversely transform the transformed values in the transformer 130.
  • the residual values generated by the inverse quantizer 140 and the inverse transformer 145 are reconstructed by being combined with prediction units predicted by the motion estimator, the motion compensator, and the intra predictor included in the predictors 120 and 125. You can create a Reconstructed Block.
  • the filter unit 150 may include at least one of a deblocking filter, an offset correction unit, and an adaptive loop filter (ALF).
  • a deblocking filter may include at least one of a deblocking filter, an offset correction unit, and an adaptive loop filter (ALF).
  • ALF adaptive loop filter
  • the deblocking filter may remove block distortion caused by boundary between blocks in the reconstructed picture.
  • it may be determined whether to apply a deblocking filter to a current block based on pixels included in a few columns or rows included in the block.
  • a strong filter or a weak filter may be applied according to the required deblocking filtering strength.
  • horizontal filtering and vertical filtering may be performed in parallel when performing vertical filtering and horizontal filtering.
  • the offset correction unit may correct an offset from the original image in units of pixels for the deblocking image.
  • the offset correction unit may correct an offset from the original image in units of pixels for the deblocking image. In order to perform offset correction for a specific picture, after dividing the pixels included in the image into a certain number of regions, determining the region to perform the offset and applying the offset to the region or offset by considering the edge information of each pixel You can use the method of applying.
  • Adaptive Loop Filtering may be performed based on a value obtained by comparing the filtered reconstructed image with the original image. After dividing the pixels included in the image into a predetermined group, one filter to be applied to the group may be determined to perform filtering differently for each group. For information related to whether to apply ALF, a luminance signal may be transmitted for each coding unit (CU), and the shape and filter coefficient of an ALF filter to be applied may vary according to each block. In addition, the same type (fixed form) of the ALF filter may be applied regardless of the characteristics of the block to be applied.
  • ALF Adaptive Loop Filtering
  • the memory 155 may store the reconstructed block or picture calculated by the filter unit 150, and the stored reconstructed block or picture may be provided to the predictors 120 and 125 when performing inter prediction.
  • FIG. 2 is a block diagram showing an image decoding apparatus according to an embodiment of the present invention.
  • the image decoder 200 includes an entropy decoding unit 210, a reordering unit 215, an inverse quantization unit 220, an inverse transform unit 225, a prediction unit 230, 235, and a filter unit ( 240), a memory 245 may be included.
  • the input bitstream may be decoded in a procedure opposite to that of the image encoder.
  • the entropy decoding unit 210 may perform entropy decoding in a procedure opposite to that performed by entropy encoding in the entropy encoding unit of the image encoder. For example, various methods such as Exponential Golomb (CAVLC), Context-Adaptive Variable Length Coding (CAVLC), and Context-Adaptive Binary Arithmetic Coding (CABAC) may be applied to the method performed in the image encoder.
  • CAVLC Exponential Golomb
  • CAVLC Context-Adaptive Variable Length Coding
  • CABAC Context-Adaptive Binary Arithmetic Coding
  • the entropy decoding unit 210 may decode information related to intra prediction and inter prediction performed by the encoder.
  • the rearrangement unit 215 may rearrange the bitstream entropy-decoded by the entropy decoding unit 210 based on a method of rearranging the bitstream. Coefficients expressed in the form of a one-dimensional vector may be reconstructed by reconstructing the coefficients in a two-dimensional block form.
  • the reordering unit 215 may receive information related to coefficient scanning performed by the encoding unit and perform reordering through a reverse scanning method based on a scanning order performed by the encoding unit.
  • the inverse quantization unit 220 may perform inverse quantization based on the quantization parameter provided by the encoder and the coefficient values of the rearranged blocks.
  • the inverse transform unit 225 may perform inverse transform, that is, inverse DCT, inverse DST, and inverse KLT, for transforms performed by the transform unit for the quantization results performed by the image encoder, that is, DCT, DST, and KLT.
  • the inverse transform may be performed based on the transmission unit determined by the image encoder.
  • a transform method for example, DCT, DST, KLT
  • a plurality of information such as a prediction method, a current block size, and a prediction direction.
  • the prediction units 230 and 235 may generate the prediction block based on the prediction block generation related information provided by the entropy decoder 210 and previously decoded blocks or picture information provided by the memory 245.
  • intra prediction when intra prediction is performed in the same manner as in the image encoder, when the size of the prediction unit and the size of the transformation unit are the same, the pixel located on the left side of the prediction unit, the pixel located on the top left, and the top level Intra prediction of the prediction unit is performed based on the pixel to be performed.
  • intra prediction is performed using the reference pixel based on the transformation unit. You can.
  • intra prediction using N x N splitting may be used only for the smallest coding unit.
  • the predictors 230 and 235 may include a prediction unit determiner, an inter predictor, and an intra predictor.
  • the prediction unit discrimination unit receives various information such as prediction unit information input from the entropy decoding unit 210, prediction mode information of the intra prediction method, and motion prediction related information of the inter prediction method, classifies the prediction unit from the current coding unit, and predicts the prediction unit. It is possible to determine whether the unit performs inter prediction or intra prediction.
  • the inter prediction unit 230 uses the information necessary for inter prediction of the current prediction unit provided by the image encoder to predict the current based on information included in at least one of a previous picture or a subsequent picture of the current picture including the current prediction unit. Inter prediction for a unit may be performed. Alternatively, inter prediction may be performed based on information of some regions pre-restored in the current picture including the current prediction unit.
  • a motion prediction method of a prediction unit included in a corresponding coding unit based on a coding unit is one of a skip mode, a merge mode, an AMVP mode, and an intra block copy mode. It can be judged how it is.
  • the intra predictor 235 may generate a prediction block based on pixel information in the current picture.
  • intra prediction may be performed based on intra prediction mode information of a prediction unit provided by an image encoder.
  • the intra predictor 235 may include an adaptive intra smoothing (AIS) filter, a reference pixel interpolator, and a DC filter.
  • the AIS filter is a part of filtering the reference pixel of the current block, and may determine and apply the filter according to the prediction mode of the current prediction unit.
  • AIS filtering may be performed on a reference pixel of a current block by using prediction mode and AIS filter information of a prediction unit provided by an image encoder. If the prediction mode of the current block is a mode that does not perform AIS filtering, the AIS filter may not be applied.
  • the reference pixel interpolator may generate a reference pixel having an integer value or less by interpolating the reference pixel. If the prediction mode of the current prediction unit is a prediction mode that generates a prediction block without interpolating a reference pixel, the reference pixel may not be interpolated.
  • the DC filter may generate the prediction block through filtering when the prediction mode of the current block is the DC mode.
  • the reconstructed block or picture may be provided to the filter unit 240.
  • the filter unit 240 may include a deblocking filter, an offset correction unit, and an ALF.
  • Information about whether a deblocking filter is applied to a corresponding block or picture and information about whether a strong filter is applied or a weak filter is applied may be provided from a video encoder.
  • information related to the deblocking filter provided by the video encoder may be provided, and the video decoder may perform deblocking filtering on the corresponding block.
  • the offset correction unit may perform offset correction on the reconstructed image based on the type of offset correction and offset value information applied to the image during encoding.
  • the ALF may be applied to a coding unit based on ALF application information, ALF coefficient information, and the like provided from the encoder. Such ALF information may be provided included in a specific parameter set.
  • the memory 245 may store the reconstructed picture or block to use as a reference picture or reference block, and provide the reconstructed picture to the output unit.
  • a coding unit is used as a coding unit for convenience of description, but it may be a unit for performing decoding as well as coding.
  • FIG. 3 illustrates a block division type according to an embodiment to which the present invention is applied.
  • One block (hereinafter referred to as a first block) may be divided into a plurality of sub blocks (hereinafter referred to as a second block) by at least one of a vertical line or a horizontal line.
  • the vertical line and the horizontal line may be one, two or more.
  • the first block may be a coding block (CU) that is a basic unit of image encoding / decoding, a prediction block (PU) that is a basic unit of predictive encoding / decoding, or a transform block (TU) that is a basic unit of transform encoding / decoding.
  • the first block may be a square block or a non-square block.
  • the division of the first block may be performed based on a quad tree, a binary tree, a triple tree, and the like, and will be described in detail with reference to FIG. 3.
  • QT quad tree division
  • QT is a division type that divides the first block into four second blocks. For example, when the first block of 2N ⁇ 2N is divided into QTs, the first block may be divided into four second blocks having an N ⁇ N size.
  • QT may be limited to be applied only to square blocks, but may also be applied to non-square blocks.
  • FIG. 3B illustrates a horizontal binary tree division (hereinafter referred to as Horizontal BT).
  • Horizontal BT is a division type in which the first block is divided into two second blocks by one horizontal line. The dividing may be performed symmetrically or asymmetrically. For example, when the first block of 2N ⁇ 2N is divided into Horizontal BT, the first block may be divided into two second blocks having a height ratio of (a: b).
  • a and b may be the same value, and a may be larger or smaller than b.
  • FIG. 3 (c) illustrates splitting of a vertical binary tree (hereinafter referred to as vertical BT).
  • Vertical BT is a division type in which the first block is divided into two second blocks by one vertical line. The dividing may be performed symmetrically or asymmetrically. For example, when a first block of 2N ⁇ 2N is divided into vertical BTs, the first block may be divided into two second blocks having a width ratio (a: b).
  • a and b may be the same value, and a may be larger or smaller than b.
  • Horizontal TT is a division type in which the first block is divided into three second blocks by two horizontal lines.
  • the first block may be divided into three second blocks having a height ratio of (a: b: c).
  • a, b, and c may be the same value.
  • a and c may be the same and b may be larger or smaller than a.
  • Vertical TT is a split type in which the first block is divided into three second blocks by two vertical lines.
  • the first block may be divided into three second blocks having a width ratio (a: b: c).
  • a, b, and c may be the same value, or may be different values.
  • a and c may be the same and b may be larger or smaller than a.
  • a and b may be the same and c may be larger or smaller than a.
  • b and c are the same, and a may be greater or less than b.
  • the above-described partitioning may be performed based on the partitioning information signaled from the encoding apparatus.
  • the split information may include at least one of split type information, split direction information, or split ratio information.
  • the split type information may specify any one of the split types previously defined in the encoding / decoding apparatus.
  • the pre-defined split type may include at least one of QT, Horizontal BT, Vertical BT, Horizontal TT, Vertical TT, or No split mode.
  • the partition type information may mean information on whether QT, BT or TT is applied, which may be encoded in the form of a flag or an index.
  • the split direction information may indicate whether the split direction information is split in the horizontal direction or in the vertical direction.
  • the split ratio information may indicate a ratio of width and / or height of the second block.
  • FIG. 4 is a diagram illustrating a tree structure based block partitioning method according to an embodiment to which the present invention is applied.
  • the block 400 illustrated in FIG. 4 is a square block (hereinafter, referred to as a first block) having a size of 8N ⁇ 8N and having a division depth of k.
  • the first block may be divided into four sub blocks (hereinafter, referred to as a second block).
  • the second block may be 4N ⁇ 4N in size and have a split depth of (k + 1).
  • the four second blocks may be divided again based on any one of QT, BT, TT, or non-divided mode.
  • the split information of the second block indicates a binary tree (Horizontal BT) in the horizontal direction
  • the second block may be divided into two sub-blocks (hereinafter, referred to as a third block) as shown in the second block 410 of FIG. 4.
  • the third block may have a size of 4N ⁇ 2N and have a division depth of (k + 2).
  • the third block may also be divided again based on one of QT, BT, TT, or non-split mode.
  • the third block when split information of the third block indicates a vertical tree in the vertical direction, the third block is divided into two sub-blocks 411 and 412 as shown in FIG. 4. Can be. In this case, the sub blocks 411 and 412 may have a size of 2N ⁇ 2N and have a split depth of (k + 3).
  • the partition information of the third block indicates a binary tree (Horizontal BT) in the horizontal direction
  • the third block may be divided into two sub-blocks 413 and 414 as shown in FIG. 4. have. In this case, the sub-blocks 413 and 414 may have a size of 4N ⁇ N and have a division depth of (k + 3).
  • the division may be performed independently or in parallel with neighboring blocks, or may be performed sequentially according to a predetermined priority.
  • the split information of the current block to be split may be determined based on at least one of split information of the upper block of the current block or split information of the neighboring block. For example, when the second block is divided into Horizontal BT and the upper third block is divided into Vertical BT, the lower third block need not be divided into Vertical BT. When the third block at the bottom is divided into Vertical BT, this is because the same result as the second block is divided into QT. Accordingly, encoding may be omitted in the split information (particularly, split direction information) of the lower third block, and the decoding apparatus may set the lower third block to be split in the horizontal direction.
  • the upper block may mean a block having a division depth smaller than the division depth of the current block.
  • the split depth of the current block is (k + 2)
  • the split depth of the higher block may be (k + 1).
  • the neighboring block may be a block adjacent to the top or left side of the current block.
  • the neighboring block may be a block having the same division depth as the current block.
  • the above-described division may be repeatedly performed up to the minimum unit of encoding / decoding.
  • splitting information for the corresponding block is no longer signaled from the encoding apparatus.
  • the information on the minimum unit may include at least one of the size or shape of the minimum unit.
  • the size of the minimum unit may be expressed as a minimum or maximum value of the width, height, width and height of the block, the sum of the width and height, the number of pixels, and the divided depth.
  • the information on the minimum unit may be signaled in at least one of a video sequence, a picture, a slice, or a block unit. Alternatively, the information on the minimum unit may be a value pre-committed to the encoding / decoding apparatus.
  • the information on the minimum unit may be signaled for each of CU, PU, and TU. Information on one minimum unit may be equally applied to CU, PU, and TU.
  • FIG. 5 is an exemplary diagram illustrating an intra-prediction mode pre-defined in an image encoding / decoding apparatus.
  • the pre-defined intra prediction mode may be defined as a prediction mode candidate group composed of 67 modes, specifically 65 directional modes (2 to 66) and 2 non-directional modes (DC, Planar).
  • the directional mode may be divided into slope (eg, dy / dx) or angle information (Degree). All or part of the intra prediction modes described in the above example may be included in the prediction mode candidate group of the luminance component or the color difference component, and other additional modes may be included in the prediction mode candidate group.
  • reconstructed blocks of other color spaces that have been decoded / decoded may be used for prediction of the current block, and may include a prediction mode that supports them.
  • a predicted block of the current block may be generated using a reconstructed block of a luminance component corresponding to the current block. That is, the prediction block may be generated based on the reconstructed block in consideration of the correlation between color spaces.
  • the prediction mode candidate group may be adaptively determined according to the encoding / decoding setting.
  • the number of candidate groups may be increased for the purpose of increasing the accuracy of prediction, and the number of candidate groups may be reduced for the purpose of reducing the bit amount according to the prediction mode.
  • a candidate group (67. 65 directional modes and 2 non-directional modes), B candidate group (35. 33 directional modes and 2 non-directional modes), C candidate group (18. 17 directional modes) And one non-directional mode), and can be selected or determined adaptively according to the size and shape of the block.
  • the configuration of the prediction mode candidate group may be varied according to the sub / decoding setting.
  • the prediction mode candidates are uniformly formed between modes, or the number of modes between the 18th and 34th modes in FIG. 5 constitutes more candidate groups than the number of modes between the 2nd and 18th modes. can do. Or, vice versa.
  • candidate groups may be adaptively configured.
  • the width of the current block is greater than the height, all or part of the intra prediction modes belonging to Nos. 2 to 18 are not used, and all or part of the intra prediction modes belonging to Nos. 67 to 80 may be replaced.
  • the width of the current block is smaller than the height, all or part of the intra prediction modes belonging to Nos. 50 to 66 are not used, and all or part of the intra prediction modes belonging to -14 to -1 may be replaced.
  • intra prediction setting may be changed and applied.
  • FIG 6 shows an intra prediction method as an embodiment to which the present invention is applied.
  • a reference region for intra prediction of a current block may be determined (S600).
  • the encoding / decoding device can define a plurality of pixel lines usable for intra prediction.
  • the plurality of pixel lines may include at least one of a first pixel line adjacent to the current block, a second pixel line adjacent to the first pixel line, a third pixel line adjacent to the second pixel line, or a fourth pixel line adjacent to the third pixel line. It may include.
  • the plurality of pixel lines may include all of the first to fourth pixel lines, or may include only the remaining pixel lines except the third pixel line.
  • the plurality of pixel lines may include only the first pixel line and the fourth pixel line.
  • the current block may select one or more pixel lines among the plurality of pixel lines, and use them as a reference area.
  • the selection may be performed based on an index (refIdx) signaled by the encoding apparatus.
  • the selection may be performed based on predetermined encoding information.
  • the encoding information may include at least one of the size, shape, division type of the current block, whether the intra prediction mode is a non-directional mode, whether the intra prediction mode is a horizontal direction, or an angle or component type of the intra prediction mode. have.
  • the intra prediction mode is a planar mode or a DC mode, it may be restricted to use only the first pixel line.
  • the size of the current block is less than or equal to a predetermined threshold, only the first pixel line may be restricted.
  • the size may be expressed as either the width or height of the current block (e.g., maximum value, minimum value, etc.), the sum of the width and height, or the number of samples belonging to the current block.
  • the intra prediction mode is greater than a predetermined threshold angle (or less than a predetermined threshold angle)
  • the first pixel line may be restricted to be used.
  • the threshold angle may be an angle of the intra prediction mode corresponding to mode 2 and mode 66 among the prediction mode candidate groups described above.
  • an intra prediction mode of a current block may be determined (S610).
  • the current block is a concept including a luminance block and a chrominance block, and the intra prediction mode can be determined for each of the luminance block and the chrominance block.
  • the intra prediction mode pre-defined in the decoding apparatus is composed of a non-directional mode (Planar mode, DC mode) and 65 directional modes.
  • the above-defined intra prediction mode may be divided into an MPM candidate group and a non-MPM candidate group.
  • the intra prediction mode of the current block may be derived by selectively using either the MPM candidate group or the non-MPM candidate group.
  • a flag indicating whether the current block is derived from the MPM candidate group may be used for the current block.
  • the flag may be encoded and signaled by an encoding device.
  • the flag may be derived from a decoding device based on predetermined encoding information. The encoding information is as described above, and duplicate description will be omitted.
  • the intra prediction mode of the current block may be derived based on the MPM candidate group and the MPM index.
  • the MPM candidate group includes one or more MPMs, and the MPM may be determined based on the intra prediction mode of the neighboring block of the current block.
  • the number of MPMs is r, and r may be an integer of 1, 2, 3, 4, 5, 6, or more.
  • the number of MPMs may be a fixed value that is pre-promised in the encoding / decoding device, or may be variably determined based on the aforementioned encoding information.
  • the MPM candidate group may include at least one of intra prediction mode modeA, (modeA-n), (modeA + n) or default mode of the neighboring block.
  • the n value may be an integer of 1, 2, 3, 4 or more.
  • the neighboring block may mean a block adjacent to the left and / or top of the current block. However, the present invention is not limited thereto, and the neighboring block may include at least one of blocks adjacent to the upper left, lower left, or upper right.
  • the default mode may be at least one of a planar mode, a DC mode, or a predetermined directional mode.
  • the predetermined directional mode may include at least one of a horizontal mode (modeV), a vertical mode (modeH), (modeV-k), (modeV + k), (modeH-k), or (modeH + k).
  • the MPM index may specify the same MPM as the intra prediction mode of the current block among the MPMs of the MPM candidate group. That is, the MPM specified by the MPM index may be set as the intra prediction mode of the current block.
  • the MPM candidate groups may be divided into a plurality of groups.
  • the MPM candidate groups are divided into a first group and a second group.
  • the first group may be configured with at least one of the default modes described above.
  • the first group may be configured only in a non-directional mode or may be configured only in a predetermined directional mode.
  • the first group may be composed of only the Planar mode or the DC mode only among the non-directional modes.
  • the second group may include at least one of an intra prediction mode modeA, (modeA-n), (modeA + n) or default mode of the neighboring block.
  • the n value may be an integer of 1, 2, 3, 4 or more.
  • the neighboring block may mean a block adjacent to the left and / or top of the current block. However, the present invention is not limited thereto, and the neighboring block may include at least one of blocks adjacent to the upper left, lower left, or upper right.
  • the default mode may be at least one of a planar mode, a DC mode, or a predetermined directional mode.
  • the predetermined directional mode may include at least one of a horizontal mode (modeV), a vertical mode (modeH), (modeV-k), (modeV + k), (modeH-k), or (modeH + k).
  • the second group may be set to not include MPMs belonging to the first group.
  • the intra prediction mode of the current block may be derived by selectively using either the first group or the second group.
  • a flag indicating whether or not the current block is derived from the first group may be used.
  • the intra prediction mode of the current block may be set to MPM belonging to the first group.
  • the intra prediction mode of the current block may be derived based on the second group and the MPM index.
  • the MPM index is as described above, and detailed description will be omitted.
  • the flag may be encoded and signaled by an encoding device. However, the flag may be adaptively signaled in consideration of predetermined encoding information.
  • the encoding information may include at least one of the size, shape, division type, or reference area of the current block.
  • the split type may mean whether or not intra prediction is performed in units of quad trees, binary trees, triple trees, or sub-blocks.
  • the flag may be signaled only when the reference area of the current block is the first pixel line (Embodiment 1). If the reference area of the current block is not the first pixel line, the flag is not signaled and may be set to a second value in the decoding device. Through this, when the current block does not refer to the first pixel line, it is possible to limit deriving an intra prediction mode based on the first group.
  • the flag can be signaled only when the current block does not perform intra-block intra prediction (Example 2). Conversely, when the current block performs intra prediction on a sub-block basis, the flag is not signaled and may be set as a second value in the decoding apparatus.
  • the flag may be signaled, or when both the embodiments 1 and 2 are satisfied, the flag may be set to be signaled.
  • intra prediction may be performed on a current block based on a reference region for intra prediction and an intra prediction mode (S620).
  • the intra prediction may be performed in units of sub-blocks of the current block.
  • the current block may be divided into a plurality of sub-blocks. The splitting method will be described in detail with reference to FIG. 7.
  • FIG 7 is an embodiment to which the present invention is applied, and shows an intra prediction method in sub-block units.
  • the current block may be divided into a plurality of sub-blocks.
  • the current block may correspond to a leaf node.
  • the leaf node may mean a coding block that is no longer divided into smaller coding blocks. That is, the leaf node may refer to a block that is no longer partitioned through the tree-based block partitioning described above.
  • the division may be performed based on the size of the current block (Example 1).
  • the current block 700 when the size of the current block 700 is smaller than a predetermined threshold size, the current block may be divided into two in the vertical or horizontal direction. Conversely, when the size of the current block 710 is greater than or equal to the threshold size, the current block may be divided into four in the vertical or horizontal direction.
  • the threshold size may be signaled in the encoding device or may be a fixed value pre-defined in the decoding device.
  • the threshold size is expressed as NxM, and N and M may be 4, 8, 16 or more.
  • the N and M may be the same or may be set differently from each other.
  • the current block can be divided into two or four.
  • the division may be performed based on the shape of the current block (Example 2).
  • the current block may be divided into four, otherwise, the current block may be divided into two. Conversely, if the shape of the current block is square, the current block may be divided into two, otherwise, the current block may be divided into four.
  • the current block may be divided into two or four, and otherwise, the current block may be undivided. Conversely, if the shape of the current block is square, the current block may be undivided, otherwise, the current block may be divided into two or four.
  • any one of the above-described embodiments 1 or 2 may be selectively applied and divided, or may be divided based on the combination of embodiments 1 and 2.
  • the two divisions may be divided into two directions in either the vertical or horizontal direction, and the four divisions may include four divisions in either the vertical or horizontal direction, or four divisions in the vertical and horizontal direction.
  • the present invention is not limited thereto, and the current block may be divided into three in the vertical or horizontal direction.
  • the ratio of width or height may be (1: 1: 2), (1: 2: 1) or (2: 1: 1).
  • Encoding parameters include block size / shape, division type (4 division, 2 division, 3 division), intra prediction mode, range / position of neighboring pixels for intra prediction, component type (e, g., Luminance, color difference) , It may mean the maximum / minimum size of the conversion block, conversion type (eg, conversion skip, DCT2, DST7, DCT8), and the like.
  • FIG. 8 is an embodiment to which the present invention is applied, and illustrates a method for predicting a reference based on components.
  • the current block may be classified into a luminance block and a color difference block according to the component type.
  • the chrominance block can be predicted using pixels of a pre-restored luminance block, and this is referred to as a reference between components.
  • the color difference block has a size of (nTbW x nTbH)
  • the luminance block corresponding to the color difference block has a size of (2 * nTbW x 2 * nTbH).
  • This assumes that the length ratio of the width and height of the luminance and color difference blocks is both 2: 1, but the examples described below are the same even when one of the width and height is 1: 1 and the other is 2: 1 or both are 1: 1. Or, it should be understood that it can be applied similarly.
  • an intra prediction mode of a color difference block may be determined (S800).
  • the pre-defined intra prediction mode for the color difference block may be divided into a first group and a second group.
  • the first group may be configured as a reference-based prediction mode between components
  • the second group may be configured as a pre-defined intra prediction mode for a luminance block.
  • the encoding / decoding apparatus may define at least one of INTRA_LT_CCLM, INTRA_L_CCLM, or INTRA_T_CCLM as a prediction mode based on a reference between components.
  • the intra prediction mode of the chrominance block may be derived by selectively using either the first group or the second group. The selection may be performed based on a predetermined first flag. The first flag may indicate whether the intra prediction mode of the color difference block is derived based on the first group or based on the second group.
  • the intra prediction mode of the color difference block may be determined as any one of the reference-based prediction modes between one or more components belonging to the first group.
  • an index specifying any one of the reference-based prediction modes among components belonging to the first group may be used.
  • a reference-based prediction mode between components belonging to the first group and an index allocated to each prediction mode are shown in Table 1 below.
  • Table 1 is only an example of an index allocated to each prediction mode, and is not limited thereto. That is, as shown in Table 1, indexes may be allocated in order of priority of INTRA_LT_CCLM, INTRA_L_CCLM, INTRA_T_CCLM, and indexes may be assigned in order of priority of INTRA_LT_CCLM, INTRA_T_CCLM, INTRA_L_CCLM. Alternatively, INTRA_LT_CCLM may have a lower priority order than INTRA_T_CCLM or INTRA_L_CCLM.
  • the first flag may be selectively signaled based on information indicating whether reference between components is allowed. For example, if the value of the information is 1, the first flag is signaled, otherwise, the first flag may not be signaled.
  • the information may be determined as 0 or 1 based on predetermined conditions to be described later.
  • the information may be set to 0.
  • the second flag may be signaled in at least one of a video parameter set (VPS), a sequence parameter set (SPS), a picture parameter set (PPS), or a slice header.
  • the information may be set to 1.
  • qtbtt_dual_tree_intra_flag may indicate whether the coding tree block is implicitly divided into a 64x64 sized coding block, and whether the 64x64 sized coding block is split into a dual tree.
  • the dual tree may mean a method in which the luminance component and the color difference component are divided with independent division structures.
  • the size of the coding tree block (CtbLog2Size) may be a size (e.g., 64x64, 128x128, 256x256) pre-defined in the encoding / decoding device, or may be encoded and signaled in the encoding device.
  • the information may be set to 1.
  • the first upper block is divided into Horizontal BT, and the second upper block is 64x32
  • the first upper block is divided into Horizontal BT, and the second upper block is divided into Vertical BT
  • the first upper block may be a block including the current color difference block as a lower block.
  • the depth of the first upper block is (k-n), and n may be 1, 2, 3, 4 or more.
  • the depth of the first upper block may mean only a depth according to quad-tree-based splitting or a depth according to at least one of a quad-tree, binary tree, or triple-tree splitting.
  • the second upper block is a lower block belonging to the first upper block, and may have a depth smaller than the current color difference block and a depth larger than the first upper block.
  • the depth of the second upper block is (k-m), and m may be a natural number less than n.
  • the information may be set to 0.
  • the information may be reset to 0.
  • the intra prediction mode of the color difference block may be derived as shown in Table 2 below based on information (intra_chroma_pred_mode) signaled by the encoding device.
  • the intra prediction mode of the color difference block may be determined based on the signaled information and the intra prediction mode of the luminance block.
  • mode66 may mean a diagonal mode in the upper right direction
  • mode50 may mean a vertical mode
  • mode18 may mean a horizontal mode
  • mode1 may mean a DC mode.
  • the intra prediction mode of the color difference block may be set to be the same as the intra prediction mode of the luminance block.
  • the intra prediction mode of the chrominance block is derived from the second group, the chrominance block may be predicted through the intra prediction method according to FIG. 6, and a detailed description thereof will be omitted. Referring to FIG. 8, components of the chrominance block A luminance region for cross-reference may be specified (S810).
  • the luminance region may include at least one of a luminance block or a neighboring region adjacent to the luminance block.
  • the pixel may mean a reconstructed value before the in-loop filter is applied.
  • the neighboring area may include at least one of a left neighboring area, a top neighboring area, or a top left neighboring area.
  • the setting can be performed only when the value of numSampL is greater than 0.
  • the setting may be performed only when the value of numSampT is greater than 0.
  • the setting may be performed only when the upper left area of the luminance block is available.
  • the numSampL and numSampT described above may be determined based on the intra prediction mode of the current block.
  • the current block may mean a color difference block.
  • INTRA_LT_CCLM when the intra prediction mode of the current block is INTRA_LT_CCLM, it can be derived as in Equation 1 below.
  • INTRA_LT_CCLM may refer to a mode in which the inter-component reference is performed based on regions adjacent to the left and top sides of the current block.
  • numSampT may be derived as nTbW when the upper neighboring region of the current block is available, and as otherwise, 0.
  • numSampL may be derived as nTbH when the left neighboring region of the current block is available, and as otherwise, 0.
  • the intra prediction mode of the current block is not INTRA_LT_CCLM, it can be derived as in Equation 2 below.
  • INTRA_T_CCLM means a mode in which the inter-component reference is performed based on the region adjacent to the top of the current block
  • INTRA_L_CCLM means a mode in which the inter-component reference is performed based on the region adjacent to the left side of the current block.
  • numTopRight may mean the number of all or some pixels belonging to an area adjacent to the upper right corner of the color difference block. Some of the pixels may mean available pixels among pixels belonging to the lowest pixel line of the corresponding area. The determination of availability is sequentially determined whether pixels are available from left to right, and this may be performed until unavailable pixels are found.
  • numLeftBelow may mean the number of all or some pixels belonging to an area adjacent to the lower left of the color difference block. Some of the pixels may mean available pixels among pixels belonging to the rightmost pixel line of the corresponding region. The usability determination sequentially determines whether a pixel is available from the top to the bottom, and this may be performed until a non-available pixel is found.
  • downsampling may be performed on the luminance region specified in S810 (S820).
  • the downsampling may include at least one of: 1. downsampling for a luminance block, 2. downsampling for a left neighboring region of the luminance block, or 3. downsampling for an upper neighboring region of the luminance block, and hereinafter Let's take a closer look.
  • the peripheral pixel may mean a pixel adjacent in at least one of left, right, top, or bottom sides of the corresponding pixel.
  • the pixel pDsY [x] [y] may be derived as in Equation 3 below.
  • the peripheral pixel may mean a pixel adjacent to at least one of the top or bottom of the corresponding pixel.
  • the peripheral pixel may mean a pixel adjacent in at least one of the left or right side of the corresponding pixel.
  • the pixel pDsY [0] [0] of the downsampled luminance block may be derived based on the corresponding pixel pY [0] [0] and / or surrounding pixels of the luminance block.
  • the position of the surrounding pixels may be differently determined according to whether the left / top neighbor area of the current block is available.
  • pDsY [0] [0] may be derived as in Equation 6 below.
  • pDsY [0] [0] may be derived as in Equation 7.
  • pDsY [0] [0] may be set as the corresponding pixel pY [0] [0] of the luminance block.
  • the peripheral pixel may mean a pixel adjacent to at least one of a bottom, left, right, bottom left, or bottom right of the corresponding pixel.
  • the pixel pDsY [x] [y] may be derived as in Equation 8 below.
  • Downsampling of the luminance block may be performed based on any one of Embodiments 1 and 2 described above. At this time, either of Embodiments 1 or 2 may be selected based on a predetermined flag.
  • the flag may indicate whether the downsampled luminance pixel has the same position as the original luminance pixel. For example, when the flag is the first value, the downsampled luminance pixel has the same position as the original luminance pixel. On the other hand, when the flag is the second value, the downsampled luminance pixel has the same position in the horizontal direction as the original luminance pixel, but has a position shifted by half pel in the vertical direction.
  • the peripheral pixel may mean a pixel adjacent in at least one of left, right, top, or bottom sides of the corresponding pixel.
  • the pixel pLeftDsY [y] may be derived as in Equation 10 below.
  • the pixel pLeftDsY [0] of the downsampled left neighbor area can be derived based on the corresponding pixel pY [-2] [0] and the neighboring pixels of the left neighbor area.
  • the peripheral pixel may mean a pixel adjacent in at least one of the left or right side of the corresponding pixel.
  • the pixel pLeftDsY [0] may be derived as shown in Equation 11 below.
  • the peripheral pixel may mean a pixel adjacent to at least one of a bottom, left, right, bottom left, or bottom right of the corresponding pixel.
  • the pixel pLeftDsY [y] may be derived as shown in Equation 12 below.
  • pLeftDsY [y] (pY [-1] [2 * y] + pY [-1] [2 * y + 1] + 2 * pY [-2] [2 * y] + 2 * pY [-2] [2 * y + 1] + pY [-3] [2 * y] + pY [-3] [2 * y + 1] + 4) >> 3
  • downsampling of the left neighboring region may be performed based on any one of the above-described embodiments 1 and 2.
  • either of Embodiments 1 or 2 may be selected based on a predetermined flag. The flag indicates whether the downsampled luminance pixel has the same position as the original luminance pixel, as described above.
  • downsampling for the left neighbor region may be performed only when the numSampL value is greater than 0. If the numSampL value is greater than 0, it may mean that the left neighboring region of the current block is available and the intra prediction mode of the current block is INTRA_LT_CCLM or INTRA_L_CCLM.
  • the downsampled upper neighboring region pixel pTopDsY [x] is derived based on the corresponding neighboring pixel pY [2 * x] [-2] and surrounding pixels of the upper neighboring region.
  • the peripheral pixel may mean a pixel adjacent in at least one of left, right, top, or bottom sides of the corresponding pixel.
  • the pixel pTopDsY [x] may be derived as in Equation 13 below.
  • the downsampled upper neighboring region pixel pTopDsY [x] is based on the corresponding neighboring pixel pY [2 * x] [-1] and peripheral pixels of the upper neighboring region.
  • the peripheral pixel may mean a pixel adjacent in at least one of the left or right side of the corresponding pixel.
  • the pixel pTopDsY [x] may be derived as in Equation 14 below.
  • the neighboring pixels may mean pixels adjacent to at least one of the top or bottom of the corresponding pixel.
  • the pixel pTopDsY [0] can be derived as in Equation 15 below.
  • the pixel pTopDsY [0] may be set to the pixel pY [0] [-1] of the upper neighboring area.
  • the downsampled upper neighboring region pixel pTopDsY [x] is derived based on the corresponding neighboring pixel pY [2 * x] [-2] and surrounding pixels of the upper neighboring region.
  • the peripheral pixel may mean a pixel adjacent to at least one of a bottom, left, right, bottom left, or bottom right of the corresponding pixel.
  • the pixel pTopDsY [x] may be derived as in Equation 16 below.
  • the downsampled upper neighboring region pixel pTopDsY [x] is based on the corresponding neighboring pixel pY [2 * x] [-1] and peripheral pixels of the upper neighboring region.
  • the peripheral pixel may mean a pixel adjacent in at least one of the left or right side of the corresponding pixel.
  • the pixel pTopDsY [x] may be derived as shown in Equation 17 below.
  • the neighboring pixels may mean pixels adjacent to at least one of the top or bottom of the corresponding pixel.
  • the pixel pTopDsY [0] can be derived as shown in Equation 18 below.
  • the pixel pTopDsY [0] may be set to the pixel pY [0] [-1] of the upper neighboring area.
  • downsampling of the upper neighboring region may be performed based on any one of the above-described embodiments 1 and 2.
  • either of Embodiments 1 or 2 may be selected based on a predetermined flag. The flag indicates whether the downsampled luminance pixel has the same position as the original luminance pixel, as described above.
  • downsampling for the upper neighboring region may be performed only when the numSampT value is greater than 0.
  • the numSampT value is greater than 0, it may mean that the upper neighboring region of the current block is available, and the intra prediction mode of the current block is INTRA_LT_CCLM or INTRA_T_CCLM.
  • parameters for reference between components of the color difference block may be derived (S830).
  • the parameter may include at least one of a weight or an offset.
  • the parameter may be determined in consideration of the intra prediction mode of the current block.
  • the parameter may be derived using at least one of a pixel in a luminance region or a pixel in a left / top neighbor region of a color difference block.
  • the luminance region may include a luminance block and an upper / left neighbor region of the luminance block.
  • the luminance region may refer to a region to which the downsampling described above is applied.
  • the parameter may be derived using all pixels or some pixels belonging to the neighboring regions of the luminance region and the color difference block.
  • Some pixels in the luminance region may be specified, and some pixels in the color difference block may be determined as pixels at positions corresponding to some pixels in the specified luminance region (Example 1). Some pixels in the luminance region may be extracted from the upper and left neighbor regions of the luminance block, respectively.
  • the number of some pixels extracted from the upper neighboring area may be the same as the number of some pixels extracted from the left neighboring area (numSampL), or may be different from each other depending on the size / shape of the luminance block. For example, in the N * M luminance block, when N is greater than M, numSampT is greater than numSampL, and when N is less than M, numSampT may be set to be less than numSampL.
  • numSampT or numSampL when the size of the luminance block is smaller than a predetermined threshold size, at least one of numSampT or numSampL is determined as i, and i may be a natural number of 2, 3, 4, or more. Conversely, when the size of the luminance block is larger than a predetermined threshold size, at least one of numSampT or numSampL is determined as j, and j may be a natural number greater than i (e.g., 3, 4, 5). Alternatively, some pixels may be limited to be extracted only in the upper neighboring region of the luminance block or only in the left neighboring region. Also in this case, as described above, numSampT or numSampL can be determined according to the size / shape of the luminance block.
  • the position of the some pixels may be a position pre-promised in the encoding / decoding device.
  • some of the pixels are determined to be at least one of the four pixels positioned in the odd-numbered direction from the left to the right, or determined as at least one of the four pixels positioned in the even-numbered order. You can.
  • the some pixels may include at least one of the two pixels positioned odd-numbered from left to right, and at least one of the two pixels positioned even-numbered from right to left.
  • the top / left neighbor regions of the luminance block are each composed of four pixels, some pixels may extract one or two pixels from the top / left neighbor regions, respectively.
  • the upper neighboring region it may be determined as at least one of the two pixels positioned in the odd number, or may be determined as at least one of the two pixels positioned in the even number. Alternatively, in the upper neighboring region, it may be determined to be at least one of the first and last two pixels. Some pixels may be extracted in the same manner from the left neighboring region.
  • some pixels in the neighboring region of the color difference block may be specified, and some pixels in the luminance region may be determined as pixels at positions corresponding to some pixels in the neighboring region of the color difference block (Example 2).
  • it may be determined according to a method of determining some pixels in the neighboring region of the color difference block and some pixels in the luminance region described above, and duplicate description will be omitted.
  • the maximum value and the minimum value can be calculated from the extracted some pixels for the luminance region and the color difference region, respectively.
  • the maximum value and the minimum value may be respectively determined as a maximum value and a minimum value among a plurality of some pixels.
  • the plurality of pixels may be arranged in descending order by comparing sizes between the plurality of pixels. At this time, an average between the upper t pixels may be set to a maximum value, and an average between the lower t pixels may be set to a minimum value.
  • t may be a natural number of 1, 2, 3 or more.
  • weights and / or offsets of the parameters may be derived.
  • the chrominance block may be predicted based on the downsampled luminance block and parameters (S840).
  • the chrominance block may be predicted by applying at least one of pre-derived weights or offsets to pixels of the downsampled luminance block.
  • Various methods of performing prediction may exist, and an example of the method of performing prediction based on spatial or temporal correlation may be an example.
  • methods such as extrapolation, interpolation, averaging, and copying may be used by using pre-coded / decoded pixels in an area adjacent to the target block.
  • a method such as block matching or template matching may be used in a reference region in which the target block is already encoded / decoded. In this case, the reference area may be limited to the current picture.
  • a method of block matching may be used in a pre-encoded / decoded reference region of a target block, or a method of template matching may be used.
  • the reference area may be limited to other pictures.
  • prediction may be performed based on the correlation, but in the case of the example, the prediction may be classified according to a reference region (current picture / other picture). As described above, prediction may be classified by various factors as well as the reference region. For example, a reference region, a reference location, a prediction method, etc. may be examples.
  • a predetermined directional mode, a non-directional mode, or the like may be configured as a prediction mode candidate group, and at least one of them may be selected to express prediction mode information.
  • prediction mode information may be expressed by motion vector information, reference picture information, and the like.
  • Each of the prediction methods may be activated by information indicating whether or not support is explicitly provided, or whether support is implicitly determined. In this example, it is assumed that 1 is activated implicitly (supported), and 2 is activated by information indicating whether or not it is explicitly supported.
  • prediction For prediction of a target block, prediction may be performed using one of the prediction methods, and selection information regarding this may occur. And, depending on the selected prediction method, subsequent prediction information (prediction mode information, etc.) may be generated, and various flags (syntax) may be configured for this.
  • prediction mode information For prediction of a target block, prediction may be performed using one of the prediction methods, and selection information regarding this may occur. And, depending on the selected prediction method, subsequent prediction information (prediction mode information, etc.) may be generated, and various flags (syntax) may be configured for this.
  • a unit (current block) to which an example described later is applied may be one of a coding unit, a prediction unit, and a transformation unit.
  • prediction method selection information (pred_mode_flag) is checked, and accordingly, when one of method 1 or method 2 is selected, prediction mode information (intra_mode_information or motion_information) is checked accordingly, and the prediction method and Prediction can be performed based on the prediction mode information.
  • intra_mode_information refers to a prediction mode of extrapolation, interpolation, and average, and configures the entire prediction mode as one candidate group such as intra_pred_mode to select among them, or the entire prediction mode such as mpm_flag, mpm_idx, remaining_mode, etc. according to predetermined criteria It may be possible to configure a plurality of candidate groups through division, to select a candidate group and to select among the selected candidate groups. Since the description of this can be derived through the above-described example, detailed description is omitted.
  • motion_information is among motion prediction mode (Skip / Merge / AMVP), motion vector prediction information, motion difference information, reference area selection information, motion model selection information, prediction direction information, motion vector precision (or motion vector difference precision) information It may include at least one.
  • the motion vector prediction may be predicted among motion vectors of blocks closest to the left, top, left, right, and left directions in the current picture centered on the current block, but is not limited thereto, and is not limited thereto.
  • n A motion vector of a block separated by n can also be used as a predicted value.
  • m and n may be integers of 4, 8, 16 or more, and may be greater than or equal to the width and height of the minimum prediction unit (or coding unit, transformation unit, etc.). That is, it can be predicted based on a motion vector of a pre-coded / decoded block before the current block.
  • motion vectors of blocks that are not closest to each other may be managed in a FIFO method based on an encoding order based on a current block.
  • (c, d) having a default value may be used as a prediction value of a motion vector, and may have a value of (0, 0), but is not limited thereto.
  • the motion model selection information may be composed of a candidate motion model or a non-movement motion model, which can be divided into the number of motion vectors (1, 2, 3 or more integers) representing the motion of the current block. It is not limited. Further, the motion vector precision may be an exponential power of 2, such as 1/4, 1/2, 1, 2, 4, etc., where the exponent is an integer (1, 2 or more) having a positive or negative sign including 0. Integer).
  • the prediction method selection information may be classified according to the prediction method.
  • the method of block matching No. 2
  • information related to general block matching motion_information
  • the reference area reference picture
  • it may be configured to include the current picture in the reference picture list. That is, information such as ref_idx is generated as before, but the current picture may be included in the list of candidate groups of ref_idx.
  • the above description may be applied to the P or B image type, and may be similarly applied to the I image type, but may be omitted because the information about the reference region may be implicitly determined in the I image type. For this reason, information such as ref_idx is omitted because the reference region is only the current picture, and the rest may have the same or similar information as general block matching.
  • Prediction method selection information may be generated in any image type. That is, prediction method selection information may also occur in the I image type. That is, block matching (ibc, intra block copy) may also be supported in the I image type.
  • prediction method selection information (pred_mode_flag_A) may be checked, and accordingly, it may be determined whether to refer to the current picture or another picture. If it is determined to refer to another picture (pred_mode_flag_A is Y. That is, 1), check the prediction mode information (motion_information_A) accordingly. If it is determined to refer to the current picture (pred_mode_flag_A is N. That is, 0), one of the first method or the second method may be selected. Prediction mode information (intra_mode_information or motion_information_B) according to the selected candidate may be checked. Prediction may be performed based on the prediction method and prediction mode information.
  • the prediction method selection information may include (conditionally) a plurality of flags.
  • one (pred_mode_flag_A) is used to classify the reference region
  • the other (pred_mode_flag_B) can be used to classify the prediction method (when the reference region is limited to the current picture).
  • the prediction method selection information about the other (pred_mode_flag_B) may occur conditionally.
  • pred_mode_flag_A checking process is omitted and the process of checking pred_mode_flag_B can be started immediately.
  • motion_information_A and motion_information_B may have a difference in the configuration of information on the reference area, and the configuration other than the information described below may be the same or similar.
  • motion_information_A processes reference picture information by constructing a reference picture list for a picture different from the current picture, and information related to the reference picture may be omitted in motion_information_B.
  • the forward or backward direction may be configured as candidates for the prediction direction information, and the prediction direction information may be omitted in motion_information_B.
  • motion_information_A may target spatially adjacent blocks and temporally adjacent blocks
  • motion_information_B may target spatially adjacent blocks
  • the detailed configuration of spatially adjacent blocks is the same. Or may not be the same.
  • the default values for motion vector prediction may be configured to be the same or not.
  • motion_information_A may use a motion model using 1 to 3 motion vectors as a candidate group
  • motion_information_B may use a motion model using 1 motion vector as a candidate group.
  • the range of the exponent in motion_information_A may be an integer having a positive and negative sign including 0, and the range of the exponent in motion_information_B may be an integer having a positive sign of 0 or more.
  • a reference region may be determined as a current picture or a different picture (pred_mode_flag_A).
  • pred_mode_flag_B the order can be changed, and in the I image type, a portion for selecting a reference region can be omitted.
  • the prediction method selection information (pred_mode_flag_A, pred_mode_flag_B) is checked, and it is determined whether to use the reference region as the current picture or another picture (pred_mode_flag_A), and how to predict by 1 or 2 Can be determined (pred_mode_flag_B).
  • pred_mode_flag_A the prediction method selection information
  • pred_mode_flag_B the prediction method selection information
  • prediction method selection information pred_mode_flag_A related to the reference area may be described or excluded in relation to a subsequent portion.
  • prediction method selection information may be confirmed. If the value of pred_mode_flag is 0, method 1 is selected, and prediction mode information (intra_mode_information) according to method 1 can be confirmed. If the value of pred_mode_flag is 1, method 2 referring to the current picture is selected, and prediction mode information (motion_information_B) according to method 2 can be confirmed. If the value of pred_mode_flag is 2, method 2 that refers to another picture is selected, and prediction mode information (motion_information_A) according to method 2 can be confirmed.
  • the prediction method selection information is processed with one flag, but two or more indexes for this may be defined.
  • the prediction method selection information may have a value of 0 or 1
  • the prediction method selection information may have a value of 0, 1, or 2.
  • the candidates referring to the current picture are first placed in 0 and 1, and the candidates referring to other pictures are placed in 2, so that index rearrangement according to the image type is not performed, but is not limited thereto. Indexes can be assigned in a different order.
  • the block attribute may include at least one of whether a skip mode, an image type (slice type), a block size, a prediction type, or a split type.
  • the prediction type includes a first prediction type including intra prediction and / or block matching mode (ibc mode), a second prediction type including inter prediction, and a third including intra prediction, block matching mode, and inter prediction. It can be classified as a prediction type.
  • a current block is predicted based on a pre-encoded / decoded region, and the pre-encoded / decoded region may refer to a region specified by a predetermined block vector.
  • the pre-encoded / decoded area may be an area belonging to a current picture to which the current block belongs.
  • Inter prediction is similar to the block matching mode in that it is performed based on a reference region specified by a motion vector, but inter prediction is different in that it refers to a picture located in a different time zone from the current block.
  • pred_mode_flag_A which is one of the prediction method selection information
  • pred_mode_flag_A is the current block when the current block is not encoded in the skip mode (condition 1), when the image type of the slice to which the current block belongs is not an I slice (condition 2)
  • the current block Signaling may be performed only when at least one of the size of is not 4x4 (condition 3) or the prediction type is the third prediction type (condition 4).
  • pred_mode_flag_A may not be signaled.
  • the pred_mode_flag_A may be derived based on at least one of a block size, a prediction type, or an image type in the decoding apparatus. For example, if the current block is 4x4, pred_mode_flag_A may be derived as 1. Alternatively, if the prediction type for the current block is the first prediction type, pred_mode_flag_A may be derived as 1. Or, if the prediction type for the current block is the second prediction type, pred_mode_flag_A may be derived as 0. Alternatively, if the image type of the slice to which the current block belongs is an I slice, pred_mode_flag_A may be derived as 1, otherwise, pred_mode_flag_A may be derived as 0.
  • pred_mode_flag_B which is one of prediction method selection information, may be signaled in consideration of at least one of a skip mode, an image type, a block size, a prediction mode, a prediction type, or a split type.
  • the pred_mode_flag_B may be signaled if the image type of the slice to which the current block belongs is an I slice, and the current block is not encoded in a skip mode.
  • the pred_mode_flag_B may be signaled if the image type of the slice to which the current block belongs is not an I slice, and the prediction mode of the current block is not intra prediction.
  • the pred_mode_flag_B may be signaled.
  • the pred_mode_flag_B may be signaled if the image type of the slice to which the current block belongs is not an I slice, the current block is 4x4, and the current block is not encoded in the skip mode.
  • pred_mode_flag_B may be signaled only when at least one of the width or height of the current block is less than 64.
  • the pred_mode_flag_B may be signaled only when the prediction type for the current block is not the second prediction type.
  • the pred_mode_flag_B may not be signaled.
  • the pred_mode_flag_B may be derived based on at least one of a block size, a prediction type, or an image type in the decoding apparatus. For example, if the current block is 128x128, pred_mode_flag_B may be derived as 0. Or, if the prediction type for the current block is the second prediction type, pred_mode_flag_B may be derived as 0.
  • pred_mode_flag_B may be derived as 0 or 1, otherwise, pred_mode_flag_B may be derived as 0.
  • pred_mode_flag_B may be derived based on a flag indicating whether block matching is allowed. For example, pred_mode_flag_B may be derived with the same value as the flag. The flag may be signaled in at least one of a video parameter set, a sequence parameter set, a picture parameter set, or a slice header.
  • the prediction method for the current block may be selected based on at least one of the embodiments according to FIGS. 9 to 12, and when the selected prediction method is intra prediction, intra prediction according to FIGS. 6 or 8 may be performed.
  • Exemplary methods of the present disclosure are expressed as a series of operations for clarity of description, but are not intended to limit the order in which the steps are performed, and each step may be performed simultaneously or in a different order if necessary.
  • the steps illustrated may include other steps in addition, other steps may be included in addition to the remaining steps, or other additional steps may be included in addition to some steps.
  • various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof.
  • one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), General Purpose It may be implemented by a general processor, a controller, a microcontroller, a microprocessor, and the like.
  • scope of the disclosure include software or machine-executable instructions (eg, an operating system, an application, firmware, a program, etc.) to cause an operation in accordance with various embodiments of the method to be executed on an apparatus or a computer, and such software or Instructions, and the like, including non-transitory computer-readable media that are stored and executable on a device or computer.
  • software or machine-executable instructions eg, an operating system, an application, firmware, a program, etc.
  • the present invention can be used to encode / decode video signals.

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PCT/KR2019/011556 2018-09-07 2019-09-06 인트라 예측을 이용한 영상 부호화/복호화 방법 및 장치 Ceased WO2020050685A1 (ko)

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CN202410888486.0A CN118612425A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法和传输比特流的方法
MYPI2021000976A MY207996A (en) 2018-09-07 2019-09-06 Method and device for coding/decoding image using intra prediction
CN202411273878.2A CN118945320A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法和记录介质
CN201980058354.2A CN112740675B (zh) 2018-09-07 2019-09-06 用于使用帧内预测对图像进行编码/解码的方法和装置
CN202410888659.9A CN118646869A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法和传输比特流的方法
CN202411273989.3A CN118972558A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法、记录介质、比特流传输方法
CN202411273789.8A CN118945319A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法和记录介质
CN202410888519.1A CN118646868A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法和传输比特流的方法
JP2021537422A JP2021536717A (ja) 2018-09-07 2019-09-06 イントラ予測を用いた画像符号化／復号化方法及び装置
US17/273,848 US11917195B2 (en) 2018-09-07 2019-09-06 Method and device for coding/decoding image using intra prediction
AU2019336894A AU2019336894A1 (en) 2018-09-07 2019-09-06 Method and device for coding/decoding image using intra prediction
CN202411273844.3A CN119011820A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法和记录介质
CN202411273919.8A CN118945321A (zh) 2018-09-07 2019-09-06 对图像进行编码/解码的方法和记录介质
CA3112916A CA3112916A1 (en) 2018-09-07 2019-09-06 Method and device for coding/decoding image using intra prediction
EP19857599.5A EP3849183A4 (en) 2018-09-07 2019-09-06 Method and device for coding/decoding image using intra prediction
SG11202101876RA SG11202101876RA (en) 2018-09-07 2019-09-06 Method and device for coding/decoding image using intra prediction
ZA2021/01431A ZA202101431B (en) 2018-09-07 2021-03-02 Method and device for coding/decoding image using intra prediction
PH12021550487A PH12021550487A1 (en) 2018-09-07 2021-03-02 Method and device for coding/decoding image using intra prediction
ZA2022/02999A ZA202202999B (en) 2018-09-07 2022-02-28 Method and device for coding/decoding image using intra prediction
US18/526,377 US12184894B2 (en) 2018-09-07 2023-12-01 Method and device for coding/decoding image using intra prediction
JP2024010892A JP7696463B2 (ja) 2018-09-07 2024-01-29 イントラ予測を用いた画像符号化／復号化方法及び装置
US18/754,945 US12382096B2 (en) 2018-09-07 2024-06-26 Method and device for coding/decoding image using intra prediction
US18/754,981 US20240348824A1 (en) 2018-09-07 2024-06-26 Method and device for coding/decoding image using intra prediction
US18/754,969 US12610080B2 (en) 2018-09-07 2024-06-26 Method and device for coding/decoding image using intra prediction
US19/058,341 US20250193441A1 (en) 2018-09-07 2025-02-20 Method and device for coding/decoding image using intra prediction
AU2025202193A AU2025202193A1 (en) 2018-09-07 2025-03-26 Method and device for coding/decoding image using intra prediction
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JP2025091078A JP2025124790A (ja) 2018-09-07 2025-05-30 イントラ予測を用いた画像符号化／復号化方法及び装置
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