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：US20220256150A1

公开(公告)日：2022-08-11

申请号：US17732958

申请日：2022-04-29

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/119 ,  H04N19/96 ,  H04N19/132 ,  H04N19/18 ,  H04N19/176

Abstract: A method for decoding an image according to the present document may comprises the steps of: deriving a modified transform coefficient; checking whether the tree type for a current block is a dual tree chroma; determining whether an MIP mode applies to the current block on the basis of the current block not being the dual tree chroma; determining whether an LFNST application width and an LFNST application height corresponding to the current block are 16 or greater, on the basis of the MIP mode being applied to the current block; and parsing an LFNST index on the basis of the LFNST application width and the LFNST application height being 16 or greater.

公开(公告)号：US20220182677A1

公开(公告)日：2022-06-09

申请号：US17592301

申请日：2022-02-03

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

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

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：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：US20220174273A1

公开(公告)日：2022-06-02

申请号：US17558086

申请日：2021-12-21

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Mehdi Salhifar ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N19/11 ,  H04N19/176 ,  H04N19/61 ,  H04N19/70

Abstract: Embodiments of the disclosure provide a method and apparatus for processing a video signal. Particularly, a method for decoding a video signal according to an embodiment of the disclosure may include: determining, among predefined secondary transform sets based on intra-prediction modes of a current block, a secondary transform set applied to the current block; obtaining a first syntax element indicating a secondary transform matrix applied to the current block in the determined secondary transform set; deriving a secondary inverse-transformed block by performing a secondary inverse transform on a left top region of the current block by using the secondary transform matrix specified by the first syntax element; and deriving a residual block of the current block by performing a primary inverse transform on the secondary inverse-transformed block using a primary transform matrix of the current block.

公开(公告)号：US20220159303A1

公开(公告)日：2022-05-19

申请号：US17592768

申请日：2022-02-04

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

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

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：US20220159276A1

公开(公告)日：2022-05-19

申请号：US17589215

申请日：2022-01-31

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghawan Kim ,  Jaehyun Lim

IPC: H04N19/176 ,  H04N19/18

Abstract: A video decoding method according to the present document comprises a step of deriving transform coefficients for a current block on the basis of residual information, wherein the step of deriving the transform coefficients comprises a step of deriving a zero-out block indicating a region in which effective transform coefficients may exist in the current block, wherein the zero-out block is derived on the basis of flag information indicating whether multiple transform selection (MTS), in which a plurality of transform kernels are used, can be applied to the current block.

公开(公告)号：US20220150497A1

公开(公告)日：2022-05-12

申请号：US17556099

申请日：2021-12-20

Applicant: LG Electronics Inc.

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

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

Abstract: An image decoding method includes: acquiring a multiple transform selection (MTS) index and residual information from a bitstream; deriving transform coefficients for the current block on the basis of the residual information; and generating residual samples of the current block on the basis of the MTS index and the transform coefficients, wherein the MTS index indicates a transform kernel set to be applied to the current block among transform kernel set candidates, at least one bin among bins of a bin string of the MTS index is derived on the basis of context coding, the context coding is performed on the basis of values of increase and decrease in a context index pertaining to the MTS index, and a single value of increase and decrease in the context index can be used for the context coding of the first bin among the bins of the bin string.

公开(公告)号：US20220132134A1

公开(公告)日：2022-04-28

申请号：US17572476

申请日：2022-01-10

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/132 ,  H04N19/96 ,  H04N19/159 ,  H04N19/18 ,  H04N19/186 ,  H04N19/176

Abstract: An image decoding method according to the present document can comprise the steps of: acquiring, from a bitstream, intra prediction mode information and an LFNST index; deriving, as a cross-component linear model (CCLM) mode, an intra prediction mode of a chroma block on the basis of the intra prediction mode information; changing the intra prediction mode of the chroma block from the CCLM mode to an intra prediction mode of a luma block corresponding to the chroma block; determining an LFNST set, including LFNST matrices, on the basis of the intra prediction mode of the luma block; selecting one of the LFNST matrices on the basis of the LFNST set and the LFNST index; and deriving transform coefficients for the chroma block on the basis of the selected LFNST matrix.

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.