公开(公告)号：US20220272383A1

公开(公告)日：2022-08-25

申请号：US17743187

申请日：2022-05-12

Applicant: LG Electronics Inc.

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

IPC: H04N19/61 ,  H04N19/124 ,  H04N19/132 ,  H04N19/18 ,  H04N19/159 ,  H04N19/122 ,  H04N19/176 ,  H04N19/129 ,  H04N19/11

Abstract: An image decoding method according to the present specification comprises the steps of: deriving transform coefficients through inverse quantization on the basis of quantized transform coefficient for a target block; deriving modified transform coefficients on the basis of 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 the step of deriving the modified transform coefficients is characterized in deriving 16 modified transform coefficients by applying a transform kernel matrix to 8 transform coefficients in a 4×4 region of the target block.

公开(公告)号：US20220109878A1

公开(公告)日：2022-04-07

申请号：US17428016

申请日：2020-02-06

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/625 ,  H04N19/176 ,  H04N19/119 ,  H04N19/12 ,  H04N19/157

Abstract: A method and device for processing a video signal using a reduced transform are provided. A method for decoding a video signal includes splitting a current block into a plurality of subblocks based on a first flag for a split direction of the current block, determining a subblock, to which a transform is applied, among the plurality of subblocks based on a second flag for a position of a transform target block, determining a transform target area in the subblock, and applying an inverse transform including a horizontal transform and a vertical transform to transform coefficients of the transform target area. The transform target area is determined based on a transform type applied to the subblock and a size of the subblock.

公开(公告)号：US20220078449A1

公开(公告)日：2022-03-10

申请号：US17526930

申请日：2021-11-15

Applicant: LG ELECTRONICS INC.

Inventor： Mehdi SALEHIFAR ,  Seunghwan KIM

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

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：US20220021884A1

公开(公告)日：2022-01-20

申请号：US17296154

申请日：2019-12-06

Applicant: LG ELECTRONICS INC.

Inventor： Seethal PALURI ,  Seunghwan KIM ,  Mehdi SALEHIFAR

IPC: H04N19/137 ,  H04N19/105 ,  H04N19/159 ,  H04N19/70 ,  H04N19/176

Abstract: A method and device for processing a video signal are disclosed. More specifically, a method of processing a video signal based on inter prediction may include when a motion vector prediction (MVP) mode is applied to a current block, deriving a motion vector predictor based on motion information of a neighboring block of the current block; in a pre-defined layer structure in which at least one combination of horizontal and vertical components of a motion vector difference is distinguished by a plurality of layers, obtaining layer information indicating a current layer to which a motion vector difference used in inter prediction of the current block belongs; obtaining index information indicating a specific combination in the current layer; deriving the motion vector difference of the current block based on the layer information and the index information; deriving a motion vector of the current block based on the motion vector predictor and the motion vector difference; and generating a prediction block of the current block based on the motion vector of the current block.

公开(公告)号：US20210258593A1

公开(公告)日：2021-08-19

申请号：US17232719

申请日：2021-04-16

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/44 ,  H04N19/159 ,  H04N19/176 ,  H04N19/625 ,  H04N19/70

Abstract: A method and a device for processing a video signal are disclosed. In particular, a method for decoding a video signal includes parsing a first syntax element indicating a primary transform kernel applied to a primary transform of a current block; determining whether a secondary transform is applicable to the current block based on the first syntax element; if the secondary transform is applicable to the current block, parsing a second syntax element indicating a secondary transform kernel applied to a secondary transform of the current block; deriving a secondary inverse-transformed block, by performing a secondary inverse-transform for a top-left specific region of the current block using a secondary transform kernel indicated by the second syntax element; and deriving a residual block of the current block, by performing a primary inverse-transform for the secondary inverse-transformed block using a primary transform kernel indicated by the first syntax element.

公开(公告)号：US20210235121A1

公开(公告)日：2021-07-29

申请号：US17058873

申请日：2019-05-31

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/625 ,  H04N19/62

Abstract: The present disclosure provides a method for reconstructing a video signal through a low-complexity Discrete Sine Transform-7 (DST7) design, including: obtaining a transform index of a current block from the video signal, wherein the transform index corresponds to any one of a plurality of transform combinations including combinations of DST7 and/or a Discrete Cosine Transform-8 (DCT8); deriving a transform combination corresponding to the transform index, wherein the transform combination includes a horizontal transform and a vertical transform, and wherein the horizontal transform and the vertical transform correspond to any one of the DST7 and the DCT8; performing an inverse transform on the current block in a vertical or horizontal direction using the DST7 or the DCT8; and reconstructing the video signal using the inverse transformed current block, wherein a 33-point Discrete Fourier Transform (DFT) is applied to the DST7 when the DST7 is 16×16 and a 65-point DFT is applied to the DST7 when the DST7 is 32×32.

公开(公告)号：US20210211729A1

公开(公告)日：2021-07-08

申请号：US17209854

申请日：2021-03-23

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/625 ,  H04N19/70 ,  H04N19/132 ,  H04N19/176

Abstract: Disclosed is a method for encoding/decoding video signals and an apparatus therefor. Specifically, a method for decoding a video signal based on reduced transform comprised the steps of: obtaining, from the video signal, a transform index indicating transform kernels applied to horizontal and vertical directions of a current block; determining a region in which a transform is applied to the current block based on the transform kernels indicated by the transform index and a size of the current block; deriving, as zero, coefficients of a remaining region other than the region to which the transform is applied within the current block; and performing an inverse transform on the region to which the transform is applied using the transform kernels indicated by the transform index.

公开(公告)号：US20210120252A1

公开(公告)日：2021-04-22

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 ,  H04N19/129 ,  H04N19/593 ,  H04N19/61 ,  H04N19/91 ,  H04N19/176 ,  H04N19/124 ,  H04N19/184 ,  H04N19/159

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：US20210021871A1

公开(公告)日：2021-01-21

申请号：US17042722

申请日：2019-05-01

Applicant: LG Electronics Inc.

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

IPC: H04N19/61 ,  H04N19/625 ,  H04N19/159 ,  H04N19/176

Abstract: The present disclosure provides a method for reconstructing a video signal based on low-complexity transform implementation including obtaining a transform index of a current block from the video signal, wherein the transform index corresponds to any one of a plurality of transform combinations including a combination of DST4 and/or DCT4; deriving a transform combination corresponding to the transform index, wherein the transform combination includes a horizontal transform and a vertical transform, and wherein the horizontal transform and the vertical transform correspond to at least one of the DST4 or the DCT4; performing an inverse transform in a vertical direction with respect to the current block by using the DST4; performing an inverse transform in a horizontal direction with respect to the current block by using the DCT4; and reconstructing the video signal by using the current block which the inverse transform is performed.