公开(公告)号：US20220353503A1

公开(公告)日：2022-11-03

申请号：US17851953

申请日：2022-06-28

Applicant: LG ELECTRONICS INC.

Inventor： Hyeongmoon JANG ,  Junghak NAM ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/13 ,  H04N19/119 ,  H04N19/124 ,  H04N19/176 ,  H04N19/61

Abstract: The present invention discloses a method for encoding/decoding a video signal and an apparatus for the method. More specifically, a method for decoding a video signal comprises generating a residual block of a current block by performing entropy decoding on the video signal; if size of the current block is smaller than a predetermined first size, parsing a transform skip flag which indicates whether a transform skip is applied to the current block; determining whether to parse a primary transform flag which indicates whether a primary transform is applied to the current block; if it is determined to parse the primary transform flag, parsing the primary transform flag; and if the primary transform flag indicates that a primary transform is applied to the current block, generating a primary inverse transformed transform block of the current block by performing a primary inverse transform to the residual block.

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：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：US20220295078A1

公开(公告)日：2022-09-15

申请号：US17829548

申请日：2022-06-01

Applicant: LG Electronics Inc.

Inventor： Joonyoung PARK ,  Byeongmoon JEON ,  Yongjoon JEON ,  Seungwook PARK ,  Jungsun KIM ,  Jaehyun LIM ,  Hendry HENDRY ,  Naeri PARK ,  Chulkeun KIM

IPC: H04N19/159 ,  H04N19/176 ,  H04N19/593 ,  H04N19/11 ,  H04N19/44

Abstract: A method for decoding an image according to the present invention comprises the steps of: receiving and decoding MPM index information for indicating an MPM candidate which is to be used as an intra prediction mode of a current block; generating an MPM candidate list containing a plurality of MPM candidates for the current block; determining the MPM candidate indicated by the decoded MPM index information as the intra prediction mode of the current block, among the plurality of the MPM candidates which constitute the MPM candidate list; and generating a prediction block corresponding to the current block by performing intra prediction for the current block based on the determined intra prediction mode.

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：US20220264104A1

公开(公告)日：2022-08-18

申请号：US17732087

申请日：2022-04-28

Applicant: LG Electronics Inc.

Inventor： Jungah CHOI ,  Jaehyun LIM ,  Jin HEO ,  Sunmi YOO ,  Ling LI ,  Jangwon CHOI ,  Seunghwan KIM

IPC: H04N19/132 ,  H04N19/105 ,  H04N19/176 ,  H04N19/18 ,  H04N19/46 ,  H04N19/70 ,  H04N19/88

Abstract: An image decoding method performed by a decoding device, according to the present document, comprises the steps of: receiving a bitstream including residual information of a current block; deriving a specific number of context-encoding bins for context syntax elements for a current sub-block of the current block; decoding the context syntax elements for the current sub-block included in the residual information on the basis of the specific number; deriving transform coefficients for the current sub-block on the basis of the decoded context syntax elements; deriving residual samples for the current block on the basis of the transform coefficients; and generating a reconstructed picture on the basis of the residual samples.

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：US20220191536A1

公开(公告)日：2022-06-16

申请号：US17688076

申请日：2022-03-07

Applicant: LG Electronics Inc.

Inventor： Naeri PARK ,  Jaehyun LIM ,  Junghak NAM

IPC: H04N19/513 ,  H04N19/103 ,  H04N19/44 ,  H04N21/235 ,  H04N19/537 ,  H04N19/119 ,  H04N19/176

Abstract: A video decoding method performed by a decoding apparatus comprises deriving control points (CPs) for the current block; obtaining motion vectors for the CPs; deriving a motion vector of a sub-block or a sample unit in the current block on the basis of the obtained motion vectors; deriving a prediction sample for the current block on the basis of the derived motion vector; and generating a reconstruction sample on the basis of the prediction sample. The method enables effective performance of inter prediction through the motion vectors (transformation prediction), not only when an image in the current block is moved in a plane, but also when the image in the current block is rotated, zoomed in, zoomed out, or transformed into a parallelogram. Accordingly, the amount of data for the residual signal for the current block can be eliminated or reduced, and the overall coding efficiency can be improved.

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.