公开(公告)号：US20220150503A1

公开(公告)日：2022-05-12

申请号：US17588075

申请日：2022-01-28

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Seunghwan Kim

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

Abstract: An image decoding method according to the present document comprises the step of: deriving transform coefficients of a current block on the basis of residual information, wherein the residual information includes first flag information indicating whether a sub-block transform of splitting and transforming a coding unit is applied to the current block, and the step of deriving the transform coefficients comprises the step of, when the first flag information is 1, deriving a zero-out block indicating an area of the current block, in which a valid transform coefficient can exist, on the basis of whether a multiple transform selection (MTS) using multiple transform kernels is applied to the current block.

公开(公告)号：US20220124370A1

公开(公告)日：2022-04-21

申请号：US17562227

申请日：2021-12-27

Applicant: LG Electronics Inc.

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

IPC: H04N19/60 ,  H04N19/132 ,  H04N19/176 ,  H04N19/184 ,  H04N19/70

Abstract: A video decoding method performed by a decoding apparatus according to the present document comprises the steps of: receiving a bit stream including residual information of a current block; deriving a specific number of the 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：US11303919B2

公开(公告)日：2022-04-12

申请号：US16863871

申请日：2020-04-30

Applicant: LG Electronics Inc.

Inventor： Naeri Park ,  Jaehyun Lim ,  Junghak Nam

IPC: H04N19/44 ,  H04N21/235 ,  H04N19/537 ,  H04N19/513 ,  H04N19/103 ,  H04N19/119 ,  H04N19/176

Abstract: A video decoding method performed by a decoding apparatus comprises deriving control points (CPs) for the current block; obtaining motion vectors for the CPs; deriving a motion vector of a sub-block or a sample unit in the current block on the basis of the obtained motion vectors; deriving a prediction sample for the current block on the basis of the derived motion vector; and generating a reconstruction sample on the basis of the prediction sample. The method enables effective performance of inter prediction through the motion vectors (transformation prediction), not only when an image in the current block is moved in a plane, but also when the image in the current block is rotated, zoomed in, zoomed out, or transformed into a parallelogram. Accordingly, the amount of data for the residual signal for the current block can be eliminated or reduced, and the overall coding efficiency can be improved.

公开(公告)号：US11297347B2

公开(公告)日：2022-04-05

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：US11290748B2

公开(公告)日：2022-03-29

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：US11290747B2

公开(公告)日：2022-03-29

申请号：US17327242

申请日：2021-05-21

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Seunghwan Kim

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

Abstract: An image decoding method 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 a restoration picture on the basis of residual samples for the target block, on the basis of an inverse primary transform for the modified transform coefficients, wherein the inverse RST is performed on the basis of: transform sets determined by a mapping relation according to an intra prediction mode applied to the target block; and a transform kernel matrix selected from among two transform kernel matrices included in each of the transform sets, and is performed on the basis of: whether the inverse RST is applied; and a transform index for indicating any one of the transform kernel matrices included in the transform sets.

公开(公告)号：US20220070498A1

公开(公告)日：2022-03-03

申请号：US17521726

申请日：2021-11-08

Applicant: LG ELECTRONICS INC.

Inventor： Hyeongmoon Jang ,  Junghak Nam ,  Jaehyun Lim

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

Abstract: An image decoding method performed by a decoding apparatus according to the present disclosure comprises the steps of: decoding, on the basis of a bitstream, an affine flag that indicates whether affine prediction is applicable to a current block and a sub-block TMVP flag that indicates whether a temporal motion vector predictor based on a sub-block of the current block is usable; determining whether to decode a predetermined merge mode flag that indicates whether to apply a predetermined merge mode to the current block, on the basis of the decoded affine flag and the decoded sub-block TMVP flag; deriving prediction samples of the current block on the basis of the determining of whether to decode the predetermined merge mode flag; and generating reconstructed samples of the current block based on the prediction samples of the current block.

公开(公告)号：US11252420B2

公开(公告)日：2022-02-15

申请号：US16954026

申请日：2018-12-13

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/18 ,  H04N19/176 ,  H04N19/184 ,  H04N19/46 ,  H04N19/60 ,  H04N19/91

Abstract: An image information decoding method performed by means of a decoding device according to the present invention comprises the steps of: decoding a non-separable secondary transform (NSST) index from a bitstream if NSST is applied to a target block; decoding information relating to transform coefficients with respect to the target block from the bitstream on the basis of the decoded NSST index; and deriving the transform coefficients with respect to the target block on the basis of the decoded information relating to the transform coefficients, wherein the NSST index is decoded prior to the information relating to the transform coefficients with respect to the target block.

公开(公告)号：US11197026B2

公开(公告)日：2021-12-07

申请号：US17028433

申请日：2020-09-22

Applicant: LG Electronics Inc.

Inventor： Jungsun Kim ,  Seungwook Park ,  Jaehyun Lim ,  Joonyoung Park ,  Younghee Choi ,  Jaewon Sung ,  Byeongmoon Jeon ,  Yongjoon Jeon

IPC: H04N19/593 ,  H04N19/196 ,  H04N19/176 ,  H04N19/70 ,  H04N19/122 ,  H04N19/61 ,  H04N19/11 ,  H04N19/186 ,  H04N19/157 ,  H04N19/80 ,  H04N19/107 ,  H04N19/172 ,  H04N19/174 ,  H04N19/59 ,  H04N19/96

Abstract: A method for signalling an intra chroma prediction mode and a method for implementing the signalled intra chroma prediction mode, the intra chroma prediction mode taking an intropolation of previously predicted luma samples from neighboring blocks of video data to attain an intra chroma prediction of a current chroma prediction unit.

公开(公告)号：US11178417B2

公开(公告)日：2021-11-16

申请号：US17138722

申请日：2020-12-30

Applicant: LG ELECTRONICS INC.

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

IPC: H04N11/02 ,  H04N19/44 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/61

Abstract: Disclosed is a method for decoding a video signal, including: generating a dequantized transform block by performing dequantization for a current block; acquiring an intra prediction mode of the current block; determining a secondary transform set applied to the current block among a plurality of secondary transform sets based on the intra prediction mode; deriving a transform kernel applied to the current block in the determined secondary transform set; and performing secondary transform for a top left specific area of the dequantized transform block by using the derived transform kernel, in which the plurality of secondary transform sets may include at least one mixed secondary transform set.