公开(公告)号：US20220248018A1

公开(公告)日：2022-08-04

申请号：US17719925

申请日：2022-04-13

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun Lim ,  Junghak Nam ,  Seunghwan Kim

IPC: H04N19/12 ,  H04N19/132 ,  H04N19/159 ,  H04N19/61 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document comprises a step for performing inverse first-order transform and inverse non-separable transform on a residual sample. The inverse non-separable transform is performed on the basis of a transform index indicating a predetermined transform kernel matrix, the inverse first-order transform is performed on the basis of a multiple transform selection (MTS) index indicating MTS for a horizontal transform kernel and a vertical transform kernel, and a syntax element bin string for the transform index is derived on the basis of first context information when a tree type for a split structure of a target block is not a single tree type and is derived on the basis of second context information when the tree type is the single tree type.

公开(公告)号：US20220174324A1

公开(公告)日：2022-06-02

申请号：US17673201

申请日：2022-02-16

Applicant: LG ELECTRONICS INC.

Inventor： Jungah Choi ,  Jin Heo ,  Sunmi Yoo ,  Jaehyun Lim ,  Jangwon Choi ,  Seunghwan Kim

IPC: H04N19/70 ,  H04N19/46 ,  H04N19/132 ,  H04N19/18 ,  H04N19/176

Abstract: An image decoding method performed by a decoding apparatus, according to the present document, comprises the steps of: acquiring syntax elements for a first transform coefficient through an n-th transform coefficient of a current block, wherein the syntax elements are syntax elements according to a first residual data coding structure of TSRC; and acquiring syntax elements for an n+1st transform coefficient through a last transform coefficient of the current block, wherein the syntax elements are syntax elements according to a second residual data coding structure of the TSRC, wherein the number of context-coded syntax elements for the first transform coefficient through the n-th transform coefficient is equal to the maximum number of context-coded bins of the current block, and the syntax elements according to the second residual data coding structure include coefficient level information and a sign flag for a transform coefficient.

公开(公告)号：US11350130B2

公开(公告)日：2022-05-31

申请号：US17047849

申请日：2019-04-17

Applicant: LG Electronics Inc.

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

IPC: H04N19/00 ,  H04N19/61 ,  H04N19/159 ,  H04N19/176 ,  H04N19/625

Abstract: The present invention provides a method for reconstructing a video signal by using an approximation transform on the basis of a preprocessing/postprocessing matrix, the method comprising: obtaining a transform index of a current block from a video signal, wherein the transform index corresponds to any one of a plurality of transform combinations including at least one of DST7, DCT8, DST6, or flipped DST7, and a transform combination includes a horizontal transform and a vertical transform; deriving a primary transform for horizontal/vertical directions corresponding to the transform index; performing an inverse primary approximation transform by using the primary transform for the horizontal/vertical directions, wherein the inverse primary approximation transform is generated by multiplying the primary transform for the horizontal/vertical directions by a preprocessing matrix and a postprocessing matrix; and reconstructing the video signal by using the inverse primary approximation-transformed current block.

公开(公告)号：US11350101B2

公开(公告)日：2022-05-31

申请号：US17373114

申请日：2021-07-12

Applicant: LG Electronics Inc.

Inventor： Jungah Choi ,  Jaehyun Lim ,  Jin Heo ,  Sunmi Yoo ,  Ling Li ,  Jangwon Choi ,  Seunghwan Kim

IPC: H04N19/132 ,  H04N19/105 ,  H04N19/88 ,  H04N19/176 ,  H04N19/70 ,  H04N19/18 ,  H04N19/46

Abstract: An image decoding method performed by a decoding device, according to the present document, comprises the steps of: receiving a bitstream including residual information of a current block; deriving a specific number of context-encoding bins for context syntax elements for a current sub-block of the current block; decoding the context syntax elements for the current sub-block included in the residual information on the basis of the specific number; deriving transform coefficients for the current sub-block on the basis of the decoded context syntax elements; deriving residual samples for the current block on the basis of the transform coefficients; and generating a reconstructed picture on the basis of the residual samples.

公开(公告)号：US11336920B2

公开(公告)日：2022-05-17

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: A method for decoding a video signal based on reduced transform includes 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：US20220124338A1

公开(公告)日：2022-04-21

申请号：US17432830

申请日：2020-02-26

Applicant: LG ELECTRONICS INC.

Inventor： Jie Zhao ,  Seunghwan Kim

IPC: H04N19/132 ,  H04N19/30 ,  H04N19/169 ,  H04N19/186 ,  H04N19/176

Abstract: According to embodiment(s) disclosed in the present document, a reshaper model used in coding including LMCS can modify a value of a delta codeword on the basis of luma bit depth and perform reshaping on the basis of determination on whether or not a reshaper is linear, and thus, signaling overhead at a higher bit depth and overhead for signaling values of delta codewords for all bins can be reduced.

公开(公告)号：US11310531B2

公开(公告)日：2022-04-19

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：US11297310B2

公开(公告)日：2022-04-05

申请号：US17138494

申请日：2020-12-30

Applicant: LG ELECTRONICS INC.

Inventor： Sunmi Yoo ,  Jungah Choi ,  Jangwon Choi ,  Seunghwan Kim

IPC: H04N19/103 ,  H04N19/176 ,  H04N19/61

Abstract: A method for decoding an image according to the present document includes obtaining prediction mode information and residual related information from a bitstream, deriving prediction samples of a current block by performing prediction based on the prediction mode information, deriving residual samples of the current block based on the residual related information, and generating reconstruction samples of the current block based on the prediction samples and the residual samples, and the residual related information includes a transform skip flag based on a size of the current block and a maximum transform skip size, the transform skip flag represents whether a transform skip is applied to the current block, and information about the maximum transform skip size is obtained from the bitstream.

公开(公告)号：US20220078434A1

公开(公告)日：2022-03-10

申请号：US17526940

申请日：2021-11-15

Applicant: LG ELECTRONICS INC.

Inventor： Mehdi Salehifar ,  Seunghwan Kim

IPC: H04N19/132 ,  H04N19/159 ,  H04N19/105 ,  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：US20210400274A1

公开(公告)日：2021-12-23

申请号：US17281893

申请日：2019-10-04

Applicant: LG ELECTRONICS INC.

Inventor： Sunmi Yoo ,  Jungah Choi ,  Seunghwan Kim ,  Jangwon Choi ,  Jin Heo

IPC: H04N19/124 ,  H04N19/18 ,  H04N19/70 ,  H04N19/184 ,  H04N19/176 ,  H04N19/132

Abstract: An image decoding method according to the present document comprises the steps of: receiving a bitstream including residual information; deriving a quantized transform coefficient for a current block on the basis of the residual information included in the bitstream; deriving a residual sample for the current block on the basis of the quantized transform coefficient; and generating a reconstructed picture on the basis of the residual sample for the current block, wherein the residual information may be derived via different syntax elements depending on whether a transform has been applied to the current block.