公开(公告)号：US20230064931A1

公开(公告)日：2023-03-02

申请号：US17792122

申请日：2021-01-12

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/132 ,  H04N19/96 ,  H04N19/18 ,  H04N19/186 ,  H04N19/176

Abstract: An image decoding method according to the present document may comprise deriving transform coefficients for a current block, based on the residual information; deriving residual samples for the current block from the transform coefficients, based on LFNST or MTS; and receiving an LFNST index related to an LFNST matrix when the LFNST is applied to the current block, wherein the LFNST index is signaled at a transform unit level for the current block, after deriving the transform coefficients for the current block.

公开(公告)号：US20230063796A1

公开(公告)日：2023-03-02

申请号：US17789483

申请日：2020-12-28

Applicant: LG ELECTRONICS INC.

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

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

Abstract: An image decoding method according to the present document comprises the steps of: receiving residual information in a bitstream, wherein the residual information includes a transform skip flag for each individual component of the current block; deriving corrected transform coefficients, wherein the step for deriving includes a step for setting a variable indicating whether effective coefficients exist at positions other than that of a DC component of the current block to 0 when even one of the values of the transform skip flags for the individual components is 0, and a step for parsing an LFNST index on the basis of the variable being 0; and deriving an LFNST kernel for applying LFNST on the basis of the LFNST index, wherein the variable being 0 may indicate that effective coefficients exist at positions other than that of the DC component.

公开(公告)号：US20220417518A1

公开(公告)日：2022-12-29

申请号：US17762150

申请日：2020-09-21

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM

IPC: H04N19/132 ,  H04N19/119 ,  H04N19/18 ,  H04N19/176

Abstract: An image decoding method includes a step of deriving a residual sample, wherein the step of deriving the residual sample includes the steps of: when a current block is divided into sub-partition blocks, deriving a transform kernel for an inverse primary transform applied to a sub-partition block based on a horizontal or a vertical length of the sub-partition block; and deriving the residual sample from transform coefficients based on the transform kernel.

公开(公告)号：US20220400286A1

公开(公告)日：2022-12-15

申请号：US17892740

申请日：2022-08-22

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM

IPC: H04N19/61 ,  H04N19/18 ,  H04N19/169 ,  H04N19/176 ,  H04N19/124 ,  H04N19/186 ,  H04N19/12 ,  H04N19/70 ,  H04N19/157 ,  H04N19/132

Abstract: An image decoding method according to the present document comprises a step of deriving modified transform coefficients, wherein the step of deriving the modified transform coefficients comprises a step of setting an LFNST apply variable about whether to apply an LFNST on the basis of the tree type of the current block, a transform coefficient coding flag for each component of the current block, or a transform skip flag for each component of the current block, and can comprise a step of parsing an LFNST index on the basis of the value of the LFNST apply variable.

公开(公告)号：US20220400266A1

公开(公告)日：2022-12-15

申请号：US17775693

申请日：2020-11-09

Applicant: LG Electronics Inc.

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

IPC: H04N19/132 ,  H04N19/186 ,  H04N19/18 ,  H04N19/176 ,  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：US20220345713A1

公开(公告)日：2022-10-27

申请号：US17854540

申请日：2022-06-30

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

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

Abstract: An image decoding method according to the present document may comprise the steps of: receiving flag information, which indicates whether a scaling list is available while an LFNST is being performed, and an LFNST index and residual information for the current block; determining, on the basis of the flag information, the LFNST index, and the tree type of the current block, whether the scaling list is applicable to the current block; deriving transform coefficients for the current block from the residual information on the basis of the determination result; and applying the LFNST to the transform coefficients to derive corrected transform coefficients.

公开(公告)号：US20220248018A1

公开(公告)日：2022-08-04

申请号：US17719925

申请日：2022-04-13

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/12 ,  H04N19/132 ,  H04N19/159 ,  H04N19/61 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document comprises a step for performing inverse first-order transform and inverse non-separable transform on a residual sample. The inverse non-separable transform is performed on the basis of a transform index indicating a predetermined transform kernel matrix, the inverse first-order transform is performed on the basis of a multiple transform selection (MTS) index indicating MTS for a horizontal transform kernel and a vertical transform kernel, and a syntax element bin string for the transform index is derived on the basis of first context information when a tree type for a split structure of a target block is not a single tree type and is derived on the basis of second context information when the tree type is the single tree type.

公开(公告)号：US20220232215A1

公开(公告)日：2022-07-21

申请号：US17699731

申请日：2022-03-21

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/132 ,  H04N19/60 ,  H04N19/18 ,  H04N19/169 ,  H04N19/176

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：US20220124351A1

公开(公告)日：2022-04-21

申请号：US17562923

申请日：2021-12-27

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

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：US20220086448A1

公开(公告)日：2022-03-17

申请号：US17535090

申请日：2021-11-24

Applicant: LG Electronics Inc.

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

IPC: H04N19/132 ,  H04N19/105 ,  H04N19/18 ,  H04N19/176

Abstract: An image decoding method, according to the present document, may comprise the steps of: deriving transform coefficients for a current block on the basis of residual information; determining whether a significant coefficient is present in a second region excluding a first region in the top-left end of the current block; parsing a LFNST index from a bitstream if the significant coefficient is not present in the second region; deriving modified transform coefficients by applying a LFNST matrix, derived on the basis of the LFNST index, to transform coefficients of the first region; and deriving residual samples of the current block on the basis of an inverse primary transform of the modified transform coefficients.