公开(公告)号：US11575914B2

公开(公告)日：2023-02-07

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：US11546632B2

公开(公告)日：2023-01-03

申请号：US17415707

申请日：2019-12-19

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Seunghwan Kim

IPC: H04N19/593 ,  H04N19/11 ,  H04N19/136 ,  H04N19/159 ,  H04N19/176 ,  H04N19/196 ,  H04N19/61

Abstract: Embodiments in the present specification provide a video signal processing method and device. A method of processing a video signal according to an embodiment in the present specification comprises the steps of: acquiring an intra-prediction mode for a current block from the video signal; determining a modified intra-prediction mode from the intra-prediction mode for the current block on the basis of the width and height of and the intra-prediction mode for the current block; and applying a transform determined on the basis of the modified intra-prediction mode. The accuracy of prediction can be further improved by deriving a modified intra-prediction mode according to a wide-angle intra-prediction mode according to the shape of and an intra-prediction mode for a current block.

公开(公告)号：US11546600B2

公开(公告)日：2023-01-03

申请号：US17732126

申请日：2022-04-28

Applicant: LG Electronics Inc.

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

IPC: H04N11/02 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/186

Abstract: An image decoding method according to the present document may comprise the steps of: deriving an intra prediction mode of a chroma block as a cross-component linear model (CCLM) mode on the basis of intra prediction mode information; updating the intra prediction mode of the chroma block on the basis of an intra prediction mode of a luma block corresponding to the chroma block; when the chroma block is not square, remapping the updated intra prediction mode to a wide-angle intra prediction mode; and determining an LFNST set including LFNST matrices on the basis of the remapped intra prediction mode.

公开(公告)号：US11470316B2

公开(公告)日：2022-10-11

申请号：US17059027

申请日：2019-05-31

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/122 ,  H04N19/124 ,  H04N19/13 ,  H04N19/176 ,  H04N19/60

Abstract: The present invention provides a method for reconstructing a video signal by using a layered-givens transform, comprising the steps of: generating a transform block by performing entropy decoding and inverse quantization on a current block; performing an inverse secondary transformation on a left top specific area of the transform block by using the layered-givens transform; performing an inverse primary transformation on the block on which the inverse secondary transformation has been performed; and reconstructing the current block by using the block on which the inverse primary transformation has been performed, wherein the layered-givens transform includes a plurality of rotation layers and a permutation matrix.

公开(公告)号：US20220132164A1

公开(公告)日：2022-04-28

申请号：US17572282

申请日：2022-01-10

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N19/60 ,  H04N19/122 ,  H04N19/124 ,  H04N19/132 ,  H04N19/176 ,  H04N19/18 ,  H04N19/70

Abstract: An image decoding method according to the present document may comprise the steps of: deriving a first variable indicating whether there is a valid coefficient in a region excluding a DC region from a current block; deriving a second variable indicating whether there is a valid coefficient in a second region excluding a first region formed at the upper left end of the current block; when the first variable indicates that the valid coefficient exists in the region excluding the DC region, and the second variable indicates that the valid coefficient does not exist in the second region, parsing an LFNST index from the bitstream; and applying an LFNST matrix derived on the basis of the LFNST index to transform coefficients in the first region, to derive the modified transform coefficients.

公开(公告)号：US11284097B2

公开(公告)日：2022-03-22

申请号：US16429956

申请日：2019-06-03

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

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：US11277638B2

公开(公告)日：2022-03-15

申请号：US17329749

申请日：2021-05-25

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Jaehyun Lim

IPC: G06K9/00 ,  H04N19/61 ,  H04N19/18 ,  H04N19/124 ,  H04N19/132 ,  H04N19/176 ,  H04N19/11 ,  H04N19/159

Abstract: An image decoding method according to the present document comprises the steps of: deriving transform coefficients through inverse 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) for the transform coefficients; and generating, on the basis of an inverse primary transform for the modified transform coefficients, a restoration picture based on residual samples for the target block, wherein the modified transform coefficients derived according to the inverse RST are two-dimensionally arranged according to the order of a row priority direction or a column priority direction according to an intra prediction mode to be applied to the target block.

公开(公告)号：US11272211B2

公开(公告)日：2022-03-08

申请号：US17350790

申请日：2021-06-17

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Jaehyun Lim

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

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.

公开(公告)号：US11265557B2

公开(公告)日：2022-03-01

申请号：US17138662

申请日：2020-12-30

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：US11240536B2

公开(公告)日：2022-02-01

申请号：US16605101

申请日：2018-04-09

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Seunghwan Kim

IPC: H04N19/91 ,  H04N19/129 ,  H04N19/13 ,  H04N19/18 ,  H04N19/70

Abstract: The present disclosure provides a method for decoding a video signal, the method comprising the steps of: decoding, from a bitstream, a syntax element indicating the last non-zero region, wherein the last non-zero region represents a region including the last non-zero transform coefficient in a scan order; splitting a current block into multiple sub-regions; and based on the syntax element, determining the last non-zero region of the current block among the split sub-regions.