公开(公告)号：US20210029357A1

公开(公告)日：2021-01-28

申请号：US17043494

申请日：2019-05-02

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/122 ,  H04N19/176 ,  H04N19/625 ,  H04N19/14

Abstract: Reconstructing a video signal based on low-complexity DST7 design including obtaining a transform index of a current block from the video signal and deriving a transform combination corresponding to the transform index. The transform index corresponds to any one of a plurality of transform combinations including a combination of DST7 and/or DCT8, and the transform combination includes horizontal and vertical transforms that correspond to at least one of the DST7 or the DCT8. The reconstruction also includes performing an inverse transform in a vertical direction by using the DST7, performing an inverse transform in a horizontal direction by using the DCT8, and reconstructing the video signal by using the current block on which the inverse transform is performed. The DST7 includes Discrete Fourier Transform (DFT) and has a different type of DFT structure based on a size of the current block.

公开(公告)号：US20210014493A1

公开(公告)日：2021-01-14

申请号：US17031089

申请日：2020-09-24

Applicant: LG ELECTRONICS INC.

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

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

Abstract: The present disclosure provides a method for reconstructing a video signal, which includes: 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：US20200314426A1

公开(公告)日：2020-10-01

申请号：US16901857

申请日：2020-06-15

Applicant: LG Electronics Inc.

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

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

Abstract: An image decoding method performed by means of a decoding device according to the present disclosure comprises the steps of: deriving transform coefficients of a target block from a bitstream; deriving a non-separable secondary transform (NSST) index with respect to the target block; performing inverse transform with respect to the transform coefficients of the target block on the basis of the NSST index and thus deriving residual samples of the target block; and generating a reconstructed picture on the basis of the residual samples.

公开(公告)号：US20250168361A1

公开(公告)日：2025-05-22

申请号：US19032830

申请日：2025-01-21

Applicant: LG ELECTRONICS INC.

Inventor： Mehdi SALEHIFAR ,  Seunghwan KIM

IPC: H04N19/159 ,  H04N19/132 ,  H04N19/176 ,  H04N19/70

Abstract: An image decoding method according to the present document may comprise the steps of: receiving flag information indicating whether or not matrix-based intra prediction (MIP) is to be used for a current block; receiving matrix-based intra prediction (MIP) mode information on the basis of the flag information; generating intra prediction samples for the current block on the basis of the MIP mode information; and generating reconstructed samples for the current block on the basis of the intra prediction samples, wherein a syntax element bin string for the MIP mode information is binarized by using a truncated binarization method.

公开(公告)号：US20250088669A1

公开(公告)日：2025-03-13

申请号：US18960436

申请日：2024-11-26

Applicant: LG Electronics Inc.

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

IPC: H04N19/625 ,  H04N19/129 ,  H04N19/176 ,  H04N19/70

Abstract: Embodiments of the present invention provide a video signal processing method and device. Particularly, a method for decoding a video signal, may comprise the steps of: checking whether a transfer skip is applied to a current block; obtaining, from a video signal, a transform index for indicating a transform type set applied to the current block when the transform skip is not applied to the current block, wherein the transform type set includes transform types applied to the current block in horizontal and vertical directions; checking whether the transform type set includes DCT2; determining a region to which a primary transform is applied based on a checking result; and performing an inverse transform on the region to which the primary transform is applied in the horizontal and vertical directions using the transform types included in the transform type set.

公开(公告)号：US20250080743A1

公开(公告)日：2025-03-06

申请号：US18948289

申请日：2024-11-14

Applicant: LG ELECTRONICS INC.

Inventor： Mehdi SALEHIFAR ,  Seunghwan KIM

IPC: H04N19/132 ,  H04N19/105 ,  H04N19/159 ,  H04N19/176

Abstract: An image decoding method according to the present document can comprise the steps of: receiving flag information indicating whether a matrix-based intra prediction (MIP) is used with respect to a current block; receiving matrix-based intra prediction (MIP) mode information on the basis of the flag information; generating an intra prediction sample for the current block on the basis of the MIP mode information; and generating restoration samples for the current block on the basis of the intra prediction samples.

公开(公告)号：US20250016321A1

公开(公告)日：2025-01-09

申请号：US18893718

申请日：2024-09-23

Applicant: LG ELECTRONICS INC

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

IPC: H04N19/122 ,  H04N19/167 ,  H04N19/176 ,  H04N19/61

Abstract: The embodiments of the present disclosure provides a method and apparatus for video signal processing. A method for decoding an image signal according to an embodiment of the present disclosure may include determining an input length and an output length of a non-separable transform based on a height and a width of a current block; determining a non-separable transform matrix corresponding to the input length and the output length of a non-separable transform; and applying the non-separable transform matrix to coefficients by a number of the input length in the current block, wherein the height and the width of a current block is greater than or equal to 8, wherein, if each of the height and the width of a current block is equal to 8, the input length of the non-separable transform is determined as 8.

公开(公告)号：US20240373026A1

公开(公告)日：2024-11-07

申请号：US18773887

申请日：2024-07-16

Applicant: LG ELECTRONICS INC.

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

IPC: 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：US20240348829A1

公开(公告)日：2024-10-17

申请号：US18742373

申请日：2024-06-13

Applicant: LG Electronics Inc.

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

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

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：US20240146965A1

公开(公告)日：2024-05-02

申请号：US18545642

申请日：2023-12-19

Applicant: LG Electronics Inc.

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

IPC: H04N19/60 ,  H04N19/105 ,  H04N19/124 ,  H04N19/176 ,  H04N19/18 ,  H04N19/70

CPC classification number: H04N19/60 ,  H04N19/105 ,  H04N19/124 ,  H04N19/176 ,  H04N19/18 ,  H04N19/70

Abstract: An image decoding method performed by means of a decoding device according to the present invention comprises the steps of: deriving quantized transform coefficients with respect to a target block from a bitstream; performing inverse quantization with respect to the quantized transform coefficients with respect to the target block and deriving transform coefficients; deriving residual samples with respect to the target block on the basis of reduced inverse transform with respect to the transform coefficients; and generating a reconstructed picture on the basis of the residual samples with respect to the target block and prediction samples with respect to the target block. The reduced inverse transform is performed on the basis of a reduced inverse transform matrix. The reduced inverse transform matrix is a non-square matrix of which the number of columns is smaller than the number of rows.