公开(公告)号：US20250063186A1

公开(公告)日：2025-02-20

申请号：US18819109

申请日：2024-08-29

Applicant: LG ELECTRONICS INC.

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

IPC: 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：US20250039391A1

公开(公告)日：2025-01-30

申请号：US18918879

申请日：2024-10-17

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Hyeongmoon JANG ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/186

Abstract: An image decoding method according to the present document comprises the steps of: on the basis of an intra prediction mode of a chroma block being a cross-component linear model (CCLM) mode and an intra prediction mode of a luma block corresponding to the chroma block being a palette mode, updating the intra prediction mode of the chroma block to an intra DC mode; on the basis of the updated intra prediction mode, determining an LFNST set including LFNST matrices; and performing LFNST on the chroma block on the basis of an LFNST matrix derived from the LFNST set, wherein the intra DC mode is an intra prediction mode corresponding to a specific location within the luma block.

公开(公告)号：US20250039381A1

公开(公告)日：2025-01-30

申请号：US18913471

申请日：2024-10-11

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/122 ,  H04N19/159 ,  H04N19/18 ,  H04N19/61

Abstract: An image decoding method according to the present disclosure comprises the steps of: deriving residual samples with respect to a target block on the basis of an inverse primary transform with respect to modified transform coefficients; and on the basis of the residual samples, generating a reconstructed picture, wherein a step of deriving the modified transform coefficients may include the steps of: parsing an LFNST index on the basis of the tree-type of a current block not being a dual-tree chroma and a MIP mode not being applicable to the current block; and deriving the modified transform coefficients on the basis of the LFNST index and an LFNST matrix.

公开(公告)号：US20250024030A1

公开(公告)日：2025-01-16

申请号：US18899842

申请日：2024-09-27

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/11 ,  H04N19/176 ,  H04N19/61

Abstract: Embodiments of the present invention provide a method and apparatus for processing a video signal. A method for decoding an image signal according to an embodiment of the present invention comprises the steps of: for a current block having a width and a height different from each other, determining a modified intra prediction mode from an intra prediction mode, on the basis of a ratio between the width and the height of the current block and the intra prediction mode; determining an inverse non-separable transform set on the basis of the modified intra prediction mode; and applying an inverse non-separable transform matrix selected from the inverse non-separable transform set with respect to the top-left region of the current block, which is determined according to the width and the height of the current block.

公开(公告)号：US20240414376A1

公开(公告)日：2024-12-12

申请号：US18812345

申请日：2024-08-22

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Hyeongmoon JANG ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/61 ,  H04N19/159 ,  H04N19/167 ,  H04N19/176 ,  H04N19/186

Abstract: An image decoding method according to the present document comprises the steps of: updating an intra-prediction mode of a chroma block on the basis of an intra-prediction mode of a luma block corresponding to the chroma block on the basis of the intra-prediction mode of the chroma block being a cross-component linear model (CCLM) mode; and determining a LFNST set including LFNST matrixes on the basis of the updated intra-prediction mode, wherein the updated intra-prediction mode is derived as an intra-prediction mode corresponding to a specific position in the luma block, and the updated intra-prediction mode is updated as an intra-DC mode on the basis of the intra-prediction mode, that corresponds to the specific position, being an intra-block copy (IBC) mode.

公开(公告)号：US20240406393A1

公开(公告)日：2024-12-05

申请号：US18805322

申请日：2024-08-14

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/12 ,  H04N19/167 ,  H04N19/176 ,  H04N19/186 ,  H04N19/61 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document comprises the step of deriving modified transform coefficients by applying LFNST to transform coefficients, wherein the step of deriving the modified transform coefficients comprises the steps of: deriving a variable indicating whether an effective coefficient is present in a DC component of a current block; and parsing an LFNST index on the basis of whether the variable indicates that the effective coefficient is present in a position other than the DC component, wherein the variable may be derived on the basis of an individual transform skip flag value for a color component of the current block.

公开(公告)号：US20240373011A1

公开(公告)日：2024-11-07

申请号：US18571622

申请日：2022-06-16

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM ,  Jie ZHAO

IPC: H04N19/122 ,  H04N19/11 ,  H04N19/132 ,  H04N19/136 ,  H04N19/176 ,  H04N19/184 ,  H04N19/61

Abstract: An image decoding method according to the present document comprises a step of deriving a corrected transform coefficient by applying low-frequency non-separable transform (LFNST) to a transform coefficient, wherein an LFNST set for applying the LFNST may be derived on the basis of an intra-prediction mode applied to the current block, and an LFNST matrix may be derived on the basis of the size of the current block and the LFNST set, the LFNST matrix derived as a 16×16 dimensional matrix if the width or the height of the current block is 4 and the width and the height are both 4 or greater, and the LFNST matrix derived as a 64×32 dimensional matrix if the width or the height of the current block is 8 and the width and the height are both 8 or greater. Therefore, coding performance capable of being brought by the LFNST can be maximized within the implementation complexity permitted in forthcoming standards.

公开(公告)号：US20240357110A1

公开(公告)日：2024-10-24

申请号：US18571385

申请日：2022-06-16

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM ,  Jie ZHAO

IPC: H04N19/122 ,  H04N19/14 ,  H04N19/176 ,  H04N19/61

CPC classification number: H04N19/122 ,  H04N19/14 ,  H04N19/176 ,  H04N19/61

Abstract: An image decoding method according to this document comprises a step for deriving, for transform coefficients, modified transform coefficients on the basis of inverse secondary transformation, wherein the step for deriving the modified transform coefficients comprises a step for deriving a transform kernel to be applied to the inverse secondary transformation, the transform kernel may be derived as a 16×16 matrix on the basis of horizontal and vertical lengths of a target block being both greater than or equal to 4 and the horizontal or vertical length being 4, and the transform kernel may be derived as a 48×16 matrix on the basis of the horizontal and vertical lengths of the target block being both greater than or equal to 8 and the horizontal or vertical length being 8.

公开(公告)号：US20240323387A1

公开(公告)日：2024-09-26

申请号：US18735704

申请日：2024-06-06

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: determining whether or not an effective coefficient is present in a second area not including an upper-left first area of a current block; parsing an MTS index from a bitstream on the basis that the effective coefficient is not present in the second area; and deriving residual samples for the current block by applying a transform kernel, which is derived on the basis of the MTS index, to transform coefficients in the first area, wherein the MTS index can be parsed on the basis that the effective coefficient, which is present in a scan sub-block which is scanned for the effective coefficient, is not present in the second area.

公开(公告)号：US20240244262A1

公开(公告)日：2024-07-18

申请号：US18611214

申请日：2024-03-20

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/61 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176

CPC classification number: H04N19/619 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176

Abstract: A video decoding method according to the present document is characterized by comprising: a step for deriving transform coefficients through inverse quantization on the basis of quantized transform coefficients for a target block; a step for deriving modified transform coefficients on the basis of an inverse reduced secondary transform (RST) of the transform coefficients; and a step for 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 inverse RST using a transform kernel matrix is performed on transform coefficients of the upper-left 4×4 region of an 8×8 region of the target block, and the modified transform coefficients of the upper-left 4×4 region, upper-right 4×4 region, and lower-left 4×4 region of the 8×8 region are derived through the inverse RST.