公开(公告)号：US12063366B2

公开(公告)日：2024-08-13

申请号：US17637516

申请日：2020-09-15

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Mehdi Salehifar ,  Jaehyun Lim

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

CPC classification number: H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18

Abstract: An image decoding method according to the present document may comprise the steps of: if a current block is partitioned into sub-partition transform blocks, deriving a prediction sample of the current block on the basis of intra prediction mode information; determining an LFNST set including LFNST matrices on the basis of an intra prediction mode derived from the intra prediction mode information; selecting one of the LFNST matrices on the basis of the LFNST set and the LFNST index; deriving transform coefficients for the sub-partition transform blocks on the basis of the selected LFNST matrix; and deriving residual samples for the current block on the basis of the transform coefficients.

公开(公告)号：US20240195977A1

公开(公告)日：2024-06-13

申请号：US18584548

申请日：2024-02-22

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Jie Zhao ,  Hyeongmoon Jang ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186 ,  H04N19/46

CPC classification number: H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186 ,  H04N19/46

Abstract: An image decoding method according to the present document may comprise the steps of: receiving image information including residual information and an LFNST index from a bitstream; deriving a transform coefficient on the basis of the residual information; deriving a flag variable related to whether LFNST is applied to a current block on the basis of the LFNST index; and performing the LFNST on the basis of the flag variable and the transform coefficient, wherein the flag variable is derived for each color component of the current block.

公开(公告)号：US11973963B2

公开(公告)日：2024-04-30

申请号：US18089100

申请日：2022-12-27

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Mehdi Salehifar ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N19/18 ,  H04N19/11 ,  H04N19/122 ,  H04N19/124 ,  H04N19/129 ,  H04N19/159 ,  H04N19/176 ,  H04N19/184 ,  H04N19/593 ,  H04N19/61 ,  H04N19/91

CPC classification number: H04N19/18 ,  H04N19/11 ,  H04N19/122 ,  H04N19/124 ,  H04N19/129 ,  H04N19/159 ,  H04N19/176 ,  H04N19/184 ,  H04N19/593 ,  H04N19/61 ,  H04N19/91

Abstract: An image decoding method according to the present disclosure includes deriving transform coefficients through dequantization based on the quantized transform coefficients for the target block; deriving modified transform coefficients based on an inverse reduced secondary transform (RST) for the transform coefficients; deriving residual samples for the target block based on an inverse primary transform for the modified transform coefficients; and generating a reconstructed samples based on the residual samples, and prediction samples derived based on an intra prediction mode for the target block, wherein the inverse RST is performed based on a transform kernel matrix selected from a transform set including a plurality of transform kernel matrices, the transform set is determined based on a mapping relationship according to the intra prediction mode applied to the target block, and a plurality of intra prediction modes including the intra prediction mode of the target block are mapped to one transform set.

公开(公告)号：US11962779B2

公开(公告)日：2024-04-16

申请号：US17775683

申请日：2020-11-09

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Mehdi Salehifar ,  Jaehyun Lim

IPC: H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186 ,  H04N19/46

CPC classification number: H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186 ,  H04N19/46

Abstract: An image decoding method according to the present document comprises the steps of: deriving flag information indicating whether valid coefficients are present in a second area excluding a first area of the upper left corner of the current block; parsing an MTS index from a bitstream on the basis of the flag information indicating the absence of valid coefficients in the second area; and deriving residual samples for the current block by applying a conversion kernel derived on the basis of the MTS index to conversion coefficients of the first area, wherein the flag information may be derived by determining, for each scan sub-block in which the valid coefficients are scanned, whether the valid coefficients are present in the second area.

公开(公告)号：US11909972B2

公开(公告)日：2024-02-20

申请号：US18092828

申请日：2023-01-03

Applicant: LG Electronics Inc.

Inventor： Junghak Nam ,  Moonmo Koo ,  Jaehyun Lim ,  Seunghwan Kim

IPC: H04N19/12 ,  H04N19/132 ,  H04N19/176 ,  H04N19/18

CPC classification number: H04N19/12 ,  H04N19/132 ,  H04N19/176 ,  H04N19/18

Abstract: An image decoding method includes: acquiring a multiple transform selection (MTS) index and residual information from a bitstream; deriving transform coefficients for the current block on the basis of the residual information; and generating residual samples of the current block on the basis of the MTS index and the transform coefficients, wherein the MTS index indicates a transform kernel set to be applied to the current block among transform kernel set candidates, at least one bin among bins of a bin string of the MTS index is derived on the basis of context coding, the context coding is performed on the basis of values of increase and decrease in a context index pertaining to the MTS index, and a single value of increase and decrease in the context index can be used for the context coding of the first bin among the bins of the bin string.

公开(公告)号：US11889080B2

公开(公告)日：2024-01-30

申请号：US17840181

申请日：2022-06-14

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Mehdi Salehifar ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N19/122 ,  H04N19/167 ,  H04N19/176 ,  H04N19/18 ,  H04N19/91

CPC classification number: H04N19/122 ,  H04N19/167 ,  H04N19/176 ,  H04N19/18 ,  H04N19/91

Abstract: Techniques and systems for reconstructing a video signal, which include: obtaining a transform coefficient block by performing an entropy decoding and a dequantization for a current block; deriving a secondary transform corresponding to a specific area in the transform coefficient block, wherein the specific area represents an area including a top-left block of the transform coefficient block; performing an inverse secondary transform for each of subblocks within the specific area using the secondary transform; performing an inverse primary transform for a block which the inverse secondary transform is applied to; and reconstructing the current block using a block which the primary inverse transform is applied to.

公开(公告)号：US11765389B2

公开(公告)日：2023-09-19

申请号：US17985577

申请日：2022-11-11

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Jaehyun Lim

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

CPC classification number: 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：US20230239563A1

公开(公告)日：2023-07-27

申请号：US18128132

申请日：2023-03-29

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N19/00 ,  G06F9/48

CPC classification number: H04N23/60 ,  G06F9/4812 ,  G06F9/4881

Abstract: An image decoding method according to the present document comprises a step of deriving a corrected transform coefficient, wherein the step of deriving the corrected transform coefficient comprises the steps of: determining whether LFNST can be applied to the height and width of a divided sub-partition block when an ISP is applied to a current block; parsing a LFNST index when the LFNST can be applied; and deriving the corrected transform coefficient on the basis of the LFNST index and a LFNST matrix.

公开(公告)号：US11711533B2

公开(公告)日：2023-07-25

申请号：US17671946

申请日：2022-02-15

Applicant: LG ELECTRONICS INC.

Inventor： Seunghwan Kim ,  Mehdi Salehifar ,  Moonmo Koo ,  Jaehyun Lim

IPC: H04N19/44 ,  H04N19/176 ,  H04N19/46 ,  H04N19/625 ,  H04N19/11 ,  H04N19/119 ,  H04N19/159 ,  H04N19/105

CPC classification number: H04N19/44 ,  H04N19/105 ,  H04N19/11 ,  H04N19/119 ,  H04N19/159 ,  H04N19/176 ,  H04N19/46 ,  H04N19/625

Abstract: Provided is a method for decoding a video signal based on a reduced transform, which includes: checking whether a transform skip is applied to a current block; obtaining a transform index indicating a transform kernel of the current block from the video signal when the transform skip is not applied to the current block; determining a region where a primary transform is applied to the current block based on the transform kernel indicated by the transform index and a size of the current block; and performing an inverse primary transform on the region to which the primary transform is applied by using the transform kernel indicated by the transform index.

公开(公告)号：US11700377B2

公开(公告)日：2023-07-11

申请号：US17535095

申请日：2021-11-24

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Junghak Nam ,  Seunghwan Kim

IPC: H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186

CPC classification number: H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186

Abstract: An image decoding method according to the present document is characterized by including: a step for receiving a bitstream including residual information; a step for deriving transform coefficients for a target block on the basis of the residual information; a step for deriving corrected transform coefficients on the basis of an inverse non-separable transform of the transform coefficients; and a step for deriving residual samples for the target block on the basis of an inverse primary transform of the corrected transform coefficients, wherein the inverse non-separable transform is performed when the size of the target block is equal to or smaller than the size of a prescribed maximum transform application block.