公开(公告)号：US20220312012A1

公开(公告)日：2022-09-29

申请号：US17840181

申请日：2022-06-14

Applicant: LG ELECTRONICS INC.

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

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

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：US20220174319A1

公开(公告)日：2022-06-02

申请号：US17671788

申请日：2022-02-15

Applicant: LG Electronics Inc.

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

IPC: H04N19/60 ,  H04N19/124 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document comprises a step of deriving modified transform coefficients on the basis of an inverse reduced secondary transform (RST) regarding transform coefficients regarding a target block. The inverse RST is performed on the basis of transform sets determined on the basis of a mapping relation following an intra prediction mode applied to the target block, and a transform kernel matrix selected from two transform kernel matrices included in the transform sets, respectively, and and is performed on the basis of whether or not the inverse RST is applied, and a transform index indicating one of the transform kernel matrices included in the transform sets. A syntax element bin string regarding the transform index is decoded on the basis of a different context set according to the tree type regarding the division structure of the target block.

公开(公告)号：US20220109879A1

公开(公告)日：2022-04-07

申请号：US17551794

申请日：2021-12-15

Applicant: LG ELECTRONICS INC.

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

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

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：US20220103824A1

公开(公告)日：2022-03-31

申请号：US17344410

申请日：2021-06-10

Applicant: LG Electronics Inc.

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

IPC: H04N19/132 ,  H04N19/159 ,  H04N19/46 ,  H04N19/176

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：US20210297700A1

公开(公告)日：2021-09-23

申请号：US17327246

申请日：2021-05-21

Applicant: LG Electronics Inc.

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

IPC: H04N19/60 ,  H04N19/124 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document comprises a step of deriving modified transform coefficients on the basis of an inverse reduced secondary transform (RST) regarding transform coefficients regarding a target block. The inverse RST is performed on the basis of transform sets determined on the basis of a mapping relation following an intra prediction mode applied to the target block, and a transform kernel matrix selected from two transform kernel matrices included in the transform sets, respectively, and is performed on the basis of whether or not the inverse RST is applied, and a transform index indicating one of the transform kernel matrices included in the transform sets. A syntax element bin string regarding the transform index is decoded on the basis of a different context set according to the tree type regarding the division structure of the target block.

公开(公告)号：US20210266549A1

公开(公告)日：2021-08-26

申请号：US17316049

申请日：2021-05-10

Applicant: LG Electronics Inc.

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

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

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：US20210211727A1

公开(公告)日：2021-07-08

申请号：US17188791

申请日：2021-03-01

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/625 ,  H04N19/132 ,  H04N19/159 ,  H04N19/46 ,  H04N19/176

Abstract: An image decoding method according to the present invention comprises the steps of: deriving quantized transform coefficients for a current block from a bitstream; deriving transform coefficients by performing inverse quantization on the basis of the quantized transform coefficients; deriving residual samples for the current block by performing inverse transform on the basis of the transform coefficients; and generating a reconstructed picture on the basis of the residual samples, wherein the inverse transform comprises acquiring information relating to multiple transform selection (MTS) from the bitstream, and is performed using a transform kernel set derived on the basis of the information relating to the MTS.

公开(公告)号：US20240414338A1

公开(公告)日：2024-12-12

申请号：US18806103

申请日：2024-08-15

Applicant: LG Electronics Inc.

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

IPC: H04N19/122 ,  H04N19/124 ,  H04N19/132 ,  H04N19/136 ,  H04N19/176 ,  H04N19/18 ,  H04N19/184 ,  H04N19/61 ,  H04N19/96

Abstract: An image decoding method according to the present document can comprise the steps of: deriving a transform coefficient for a current block on the basis of residual information; determining whether an effective coefficient is in a second area that excludes the upper left first area of the current block; parsing an MTS index from a bitstream if the effective coefficient is not in the second area; and deriving a residual sample by applying, to transform coefficients of the first area, an MTS kernel derived on the basis of the MTS index.

公开(公告)号：US20240406394A1

公开(公告)日：2024-12-05

申请号：US18749048

申请日：2024-06-20

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：US20240333965A1

公开(公告)日：2024-10-03

申请号：US18738522

申请日：2024-06-10

Applicant: LG Electronics Inc.

Inventor： Seethal PALURI ,  Seunghwan KIM ,  Mehdi SALEHIFAR

IPC: H04N19/52 ,  H04N19/137 ,  H04N19/176 ,  H04N19/70

CPC classification number: H04N19/52 ,  H04N19/137 ,  H04N19/176 ,  H04N19/70

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 comprise: deriving a motion vector predictor based on motion information of a neighboring block of a current block; deriving a motion vector difference of the current block based on layer information and index information; deriving a motion vector of the current block based on the motion vector predictor and the motion vector difference; generating a prediction block of the current block based on the motion vector of the current block; and generating a reconstructed block of the current block based on the prediction block and a residual block of the current block, wherein the layer information includes at least one syntax element indicating a layer group to which the current layer belongs.