公开(公告)号：US20220345710A1

公开(公告)日：2022-10-27

申请号：US17763118

申请日：2020-10-08

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM ,  Mehdi SALEHIFAR

IPC: H04N19/132 ,  H04N19/18 ,  H04N19/176 ,  H04N19/70

Abstract: An image decoding method according to the present document may comprise the steps of: deriving residual samples by applying at least one of LFNST and MTS to transform coefficients; and generating a reconstructed picture on the basis of the residual samples, wherein the LFNST is performed on the basis of an LFNST transform set, an LFNST kernel included in the LFNST transform set, and an LFNST index indicating the LFNST kernel, a first bin of a syntax element bin string for the LFNST index is derived on the basis of different context information according to a tree type of a current block, and a second bin of the syntax element bin string is derived on the basis of preconfigured context information.

公开(公告)号：US20220337814A1

公开(公告)日：2022-10-20

申请号：US17760676

申请日：2020-09-21

Applicant: LG ELECTRONICS INC.

Inventor： Jin HEO ,  Jangwon CHOI ,  Jung Hak NAM ,  Hyeong Moon JANG ,  Moonmo KOO

IPC: H04N19/105 ,  H04N19/132 ,  H04N19/117 ,  H04N19/159 ,  H04N19/176

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method according to the present disclosure is performed by an image decoding apparatus. The image decoding method may comprise determining an intra prediction mode of a current block, determining a reference sample based on the intra prediction mode and a neighboring sample of the current block, generating the prediction block based on the reference sample, and decoding the current block based on the prediction block. The reference sample may be determined by applying at least one of first filtering or second filtering to the neighboring sample value based on the intra prediction mode.

公开(公告)号：US20220295085A1

公开(公告)日：2022-09-15

申请号：US17716772

申请日：2022-04-08

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Mehdi SALEHIFAR ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/44 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/625 ,  H04N19/70

Abstract: The present invention relates to a video signal decoding method based on a Multiple Transform Selection (MTS). The method may comprise the steps of: parsing a first syntax element representing whether MTS applies to the inverse transformation of a current block, wherein the MTS represents a transform mode which uses a transform type other than a default transform type predefined for the current block; by performing inverse quantization on the current block, deriving an inverse-quantized transform coefficient array having the width and the height of the current block; determining, on the basis of the first syntax element, a vertical transform type applying to the vertical direction of the current block, and a horizontal transform type applying to the horizontal direction of the current block; and, by performing inverse transformation on the inverse-quantized transform coefficient array by using the vertical transform type and the horizontal transform type, deriving a residual sample array having the width and the height of the current block.

公开(公告)号：US20220272383A1

公开(公告)日：2022-08-25

申请号：US17743187

申请日：2022-05-12

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM ,  Mehdi SALEHIFAR

IPC: H04N19/61 ,  H04N19/124 ,  H04N19/132 ,  H04N19/18 ,  H04N19/159 ,  H04N19/122 ,  H04N19/176 ,  H04N19/129 ,  H04N19/11

Abstract: An image decoding method according to the present specification comprises the steps of: deriving transform coefficients through inverse quantization on the basis of quantized transform coefficient for a target block; deriving modified transform coefficients on the basis of inverse reduced secondary transform (RST) of the transform coefficients; and generating a reconstructed picture on the basis of residual samples for the target block on the basis of an inverse primary transform of the modified transform coefficients, wherein the step of deriving the modified transform coefficients is characterized in deriving 16 modified transform coefficients by applying a transform kernel matrix to 8 transform coefficients in a 4×4 region of the target block.

公开(公告)号：US20220248027A1

公开(公告)日：2022-08-04

申请号：US17699411

申请日：2022-03-21

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM

IPC: H04N19/132 ,  H04N19/60 ,  H04N19/18 ,  H04N19/176

Abstract: An image decoding method includes a step of deriving a modified transform coefficient, wherein the step of deriving the modified transform coefficient includes the steps of: deriving a first variable indicating whether the transform coefficient exists in an area excluding a DC location of the current block; parsing an LFNST index based on the derivation result; and deriving the modified transform coefficient based on the LFNST index and an LFNST matrix, and based on the fact that the current block is divided into a plurality of sub-partition blocks, the LFNST index can be parsed without deriving the first variable.

公开(公告)号：US20220167018A1

公开(公告)日：2022-05-26

申请号：US17668934

申请日：2022-02-10

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO

IPC: H04N19/625 ,  H04N19/122 ,  H04N19/176 ,  H04N19/61

Abstract: The present disclosure relates to a method for decoding a video signal based on adaptive multiple transforms (AMT). The method includes: obtaining an AMT index from the video signal, where the AMT index indicates any one of a plurality of transform combinations in a transform configuration group, and the transform configuration group includes discrete sine transform type 7 (DST7) and discrete cosine transform type 8 (DCT8); deriving a transform combination corresponding to the AMT index, where the transform combination includes a horizontal transform and a vertical transform, and at least one of the DST-7 or the DCT-8; performing an inverse transform on a current block on the basis of the transform combination; and restoring the video signal by using the inversely transformed current block. The AMT represents a transform scheme that is performed based on a transform combination adaptively selected from a plurality of transform combinations.

公开(公告)号：US20220150504A1

公开(公告)日：2022-05-12

申请号：US17610985

申请日：2020-05-27

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Junghak NAM ,  Seunghwan KIM

IPC: H04N19/132 ,  H04N19/159 ,  H04N19/18 ,  H04N19/176

Abstract: An image decoding method according to the present document comprises the steps of: obtaining intra prediction mode information and an LFNST index; deriving an intra prediction mode of a current block on the basis of intra prediction mode information; when wide-angle intra prediction is applied to the current block, deriving a modified intra prediction mode by means of intra prediction mode remapping; deciding an LFNST set comprising LFNST matrices on the basis of the modified intra prediction mode; selecting one of the LFNST matrices on the basis of the LFNST set and LFNST index; and deriving transform coefficients for the current block on the basis of the selected LFNST matrix.

公开(公告)号：US20220141491A1

公开(公告)日：2022-05-05

申请号：US17573487

申请日：2022-01-11

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/61 ,  H04N19/122 ,  H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/70

Abstract: An image decoding method according to the present document may include the steps of: deriving the position of the final significant coefficient in the current block and transform coefficients for the current block on the basis of residual information; determining whether the index of a sub-block including the final significant coefficient is 0 and whether the position of the final significant coefficient in the sub-block is greater than 0; determining whether a significant coefficient exists in a second area excluding a first area at the upper left end of the current block; and parsing an LFNST index from a bitstream when the position of the final significant coefficient is determined to be greater than 0 in the sub-block in which the index is 0, and the significant coefficient does not exist in the second area.

公开(公告)号：US20220109878A1

公开(公告)日：2022-04-07

申请号：US17428016

申请日：2020-02-06

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Mehdi SALEHIFAR ,  Jaehyun LIM

IPC: H04N19/625 ,  H04N19/176 ,  H04N19/119 ,  H04N19/12 ,  H04N19/157

Abstract: A method and device for processing a video signal using a reduced transform are provided. A method for decoding a video signal includes splitting a current block into a plurality of subblocks based on a first flag for a split direction of the current block, determining a subblock, to which a transform is applied, among the plurality of subblocks based on a second flag for a position of a transform target block, determining a transform target area in the subblock, and applying an inverse transform including a horizontal transform and a vertical transform to transform coefficients of the transform target area. The transform target area is determined based on a transform type applied to the subblock and a size of the subblock.

公开(公告)号：US20220086490A1

公开(公告)日：2022-03-17

申请号：US17430496

申请日：2020-02-12

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM

IPC: H04N19/61 ,  H04N19/625 ,  H04N19/46 ,  H04N19/176

Abstract: Embodiments of the present disclosure provide a method and apparatus for processing a video signal. A method for decoding a video signal according to an embodiment of the present disclosure includes obtaining a sub-block transform (SBT) flag indicating whether an SBT is applied, wherein the SBT represents a transform applied to one of sub-blocks split from a coding unit, determining a transform unit from the coding unit based on the SBT flag, determining a size value of the transform unit as a first reference value if DST-7 (Discrete Sine Transform type 7) or DCT-8 (Discrete Cosine Transform type 8) is applied and the size value of the transform unit is greater than the first reference value and less than a third reference value and determining the size value as a second reference value if DCT-2 (Discrete Cosine Transform type 2) is applied and the size value is equal to or greater than the third reference value, wherein the third reference value is greater than the second reference value and the second reference value is greater than the first reference value, obtaining transform coefficients based on the size value, and performing an inverse transform on the transform coefficients. A data processing time and the amount of data necessary for a transform can be reduced by performing coding in consideration of a region reduced according to a block size.