公开(公告)号：US12273562B2

公开(公告)日：2025-04-08

申请号：US17974971

申请日：2022-10-27

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Seunghwan Kim

IPC: H04N19/60 ,  H04N19/12 ,  H04N19/132 ,  H04N19/172 ,  H04N19/176 ,  H04N19/18

Abstract: An image decoding method according to the present document comprises a step of deriving a residual sample for a current block on the basis of a transform coefficient, wherein the step of deriving the transform coefficient can comprise the steps of: determining whether a sub block transform for performing a transform by dividing a coding unit is applied to the current block; determining whether a multiple transform selection (MTS), for which a plurality of transform kernels are used, is applied to the current block; and setting the size of a transform block to which the transform is to be applied, on the basis of whether the sub block transform is applied to the current block and whether the multiple transform selection is applied to the current block.

公开(公告)号：US12262025B2

公开(公告)日：2025-03-25

申请号：US17963449

申请日：2022-10-11

Applicant: LG Electronics Inc.

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

IPC: H04N19/18 ,  H04N19/119 ,  H04N19/129 ,  H04N19/132 ,  H04N19/176 ,  H04N19/186 ,  H04N19/60 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document comprises: a residual coding step for parsing residual information received in a residual coding level and arranging transform coefficients for a current block according to a predetermined scanning order; a step for deriving residual samples by applying at least one of LFNST or MTS to the transform coefficients; and a step for generating a reconstructed picture on the basis of the residual samples, wherein the LFNST is performed on the basis of an LFNST index indicating an LFNST kernel, the MTS is performed on the basis of an MTS index indicating an MTS kernel, the LFNST index and the MTS index are signaled in a coding unit level, and the MTS index is signaled immediately after the signaling of the LFNST index.

公开(公告)号：US12250393B2

公开(公告)日：2025-03-11

申请号：US18386135

申请日：2023-11-01

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：US12160612B2

公开(公告)日：2024-12-03

申请号：US17914602

申请日：2021-03-23

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N11/02 ,  H04N19/122 ,  H04N19/124 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186 ,  H04N19/60 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document may comprise: a step of deriving transform coefficients for a current block by performing inverse quantization on the basis of residual information; and a step of deriving modified transform coefficients by applying LFNST to the transform coefficients, wherein the step of deriving the transform coefficients comprises a step of parsing position information of a last non-zero transform coefficient, an LFNST index related to application of the LFNST is parsed after parsing a position of the last non-zero transform coefficient, and the transform coefficients are derived after parsing the LFNST index.

公开(公告)号：US12143585B2

公开(公告)日：2024-11-12

申请号：US17344410

申请日：2021-06-10

Applicant: LG Electronics Inc.

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

IPC: H04N19/122 ,  H04N19/11 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/46

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

公开(公告)号：US12126831B2

公开(公告)日：2024-10-22

申请号：US17947047

申请日：2022-09-16

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Seunghwan Kim

IPC: H04N11/02 ,  H04N19/119 ,  H04N19/124 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/46 ,  H04N19/61

CPC classification number: H04N19/61 ,  H04N19/119 ,  H04N19/124 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/46

Abstract: An image decoding method according to the present document comprises the steps of: receiving a quantized transform coefficient for a target block and a transform index for non-separable quadratic transform; deriving transform coefficients by inversely quantizing the quantized transform coefficient; deriving corrected transform coefficients on the basis of a transform kernel matrix in a predetermined transform set indicated by the transform index; and deriving residual samples for the target block on the basis of inverse linear transform for the corrected transform coefficients, wherein when the target block is divided into a predetermined number of sub-blocks and is coded by intra prediction, the corrected transform coefficients are derived in units of the sub-blocks, and the transform index is received for the target block.

公开(公告)号：US12101509B2

公开(公告)日：2024-09-24

申请号：US18101335

申请日：2023-01-25

Applicant: LG Electronics Inc.

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

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

CPC classification number: 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：US12081763B2

公开(公告)日：2024-09-03

申请号：US18109531

申请日：2023-02-14

Applicant: LG ELECTRONICS INC.

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

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 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：US12058374B2

公开(公告)日：2024-08-06

申请号：US17962077

申请日：2022-10-07

Applicant: LG Electronics Inc.

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

IPC: H04N11/02 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/61

CPC classification number: H04N19/61 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18

Abstract: A video transform method includes: receiving a quantized transform coefficient for a target block and a transform index for a non-separated secondary transform; inverse-quantizing the quantized transform coefficient; deriving an input transform coefficient size indicating the length of the inverse-quantized transform coefficient to which the non-separated secondary transform has been applied, an output transform coefficient size indicating the length of a modified transform coefficient to which the non-separated secondary transform has been applied, and a transform set mapped to the intra mode of the target block, when the transform index does not indicate that the non-separated secondary transform is not performed; and deriving the modified transform coefficient on the basis of a matrix operation on a transform kernel matrix in the transform set indicated by the transform index, and a transform coefficient list corresponding to the input transform coefficient size.

公开(公告)号：US12052421B2

公开(公告)日：2024-07-30

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 ,  H04N19/176 ,  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.