公开(公告)号：US20220210426A1

公开(公告)日：2022-06-30

申请号：US17587910

申请日：2022-01-28

Applicant: LG Electronics Inc.

Inventor： Moonmo KOO ,  Seunghwan KIM ,  Jaehyun LIM

IPC: H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/18 ,  H04N19/30 ,  H04N19/46

Abstract: An image decoding method according to the present document comprises the steps of: receiving a quantized transform coefficient for a target block and a transform index for a non-separable secondary transform; dequantizing the quantized transform coefficients to derive transform coefficients; deriving modified transform coefficients on the basis of a matrix operation of a transform kernel matrix in a transform set indicated by the transform index and a transform coefficient list corresponding to the magnitude of dequantized transform coefficients; clipping the modified transform coefficients to a predetermined range of values; and deriving residual samples for the target block on the basis of an inverse primary transform with respect to the modified transform coefficients clipped.

公开(公告)号：US20220191546A1

公开(公告)日：2022-06-16

申请号：US17689277

申请日：2022-03-08

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：US20220182651A1

公开(公告)日：2022-06-09

申请号：US17671946

申请日：2022-02-15

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/44 ,  H04N19/176 ,  H04N19/46 ,  H04N19/625 ,  H04N19/11 ,  H04N19/119 ,  H04N19/159 ,  H04N19/105

Abstract: Provided is a method for decoding a video signal based on a reduced transform, which includes: checking whether a transform skip is applied to a current block; obtaining a transform index indicating a transform kernel of the current block from the video signal when the transform skip is not applied to the current block; determining a region where a primary transform is applied to the current block based on the transform kernel indicated by the transform index and a size of the current block; and performing an inverse primary transform on the region to which the primary transform is applied by using the transform kernel indicated by the transform index.

公开(公告)号：US20220150513A1

公开(公告)日：2022-05-12

申请号：US17581154

申请日：2022-01-21

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun Lim ,  Seunghwan Kim

IPC: H04N19/18 ,  H04N19/176 ,  H04N19/70 ,  H04N19/186 ,  H04N19/96 ,  H04N19/124 ,  H04N19/60

Abstract: An image decoding method according to the present document comprises the steps of: deriving a transform coefficient for a current block on the basis of residual information; deriving a residual sample by applying, to the transform coefficient, at least one of LFNST and MTS; and generating a reconstructed picture on the basis of the residual samples, wherein the LFNST is performed on the basis of an LFNST index indicating an LFNST kernel, the MTS is performed on the basis of an MTS index indicating an MTS kernel, and the LFNST index may be parsed before the MTS index.

公开(公告)号：US20220116605A1

公开(公告)日：2022-04-14

申请号：US17422629

申请日：2020-01-09

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Jaehyun LIM ,  Seunghwan KIM

IPC: H04N19/12 ,  H04N19/61 ,  H04N19/46 ,  H04N19/176

Abstract: Embodiments of the present invention provide a method and device for processing a video signal. A method for processing a video signal according to an embodiment of the present specification comprises the steps of: acquiring position information of a last significant coefficient according to scanning order in a transform block; and performing residual coding on the basis of the position information of the last significant coefficient. The position information of the last significant coefficient includes a first prefix for a column position of the last significant coefficient and a second prefix for a row position of the last significant coefficient; a range of the first prefix is determined on the basis of an effective width of the transform block; a range of the second prefix is determined on the basis of an effective height of the transform block; if a width of the transform block corresponds to a first size, the effective width of the transform block is determined to be a second size; if a height of the transform block corresponds to the first size, the effective height of the transform block is determined to be the second size; and the second size is configured to be smaller than the first size.

公开(公告)号：US20220109892A1

公开(公告)日：2022-04-07

申请号：US17553354

申请日：2021-12-16

Applicant: LG ELECTRONICS INC.

Inventor： Moonmo KOO ,  Seunghwan KIM

IPC: H04N19/91 ,  H04N19/129 ,  H04N19/13 ,  H04N19/18 ,  H04N19/70

Abstract: The present disclosure provides a method for decoding a video signal, the method comprising the steps of: decoding, from a bitstream, a syntax element indicating the last non-zero region, wherein the last non-zero region represents a region including the last non-zero transform coefficient in a scan order; splitting a current block into multiple sub-regions; and based on the syntax element, determining the last non-zero region of the current block among the split sub-regions.

公开(公告)号：US20220109875A1

公开(公告)日：2022-04-07

申请号：US17429518

申请日：2020-02-10

Applicant: LG Electronics Inc.

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

IPC: H04N19/60 ,  H04N19/176 ,  H04N19/105 ,  H04N19/46

Abstract: Embodiments in the present specification provide a method and device for processing video signal by using a sub-block unit transform. A method of decoding a video signal according to an embodiment of the present specification includes: a step for acquiring, from the video signal, information related to a transform of the current coding unit; and a step for applying an inverse transform, including a horizontal transform and a vertical transform, to a transform unit of the current coding unit on the basis of information related to the transform, wherein the information related to the transform includes: a first flag related to whether the current coding unit is divided into a plurality of sub-blocks; a second flag acquired on the basis of the first flag, and related to the respective sizes of the sub-blocks; a third flag acquired on the basis of the first flag, and related to dividing directions of the coding unit; and a fourth flag related to a sub-block in which a coded block flag (CBF) is present among the sub-blocks divided from the current coding unit on the basis of the second flag and the third flag.

公开(公告)号：US20220078420A1

公开(公告)日：2022-03-10

申请号：US17472137

申请日：2021-09-10

Applicant: LG ELECTRONICS INC.

Inventor： Ling LI ,  Jin HEO ,  Moonmo KOO ,  Jung Hak NAM

IPC: H04N19/119 ,  H04N19/159 ,  H04N19/176 ,  H04N19/186 ,  H04N19/593

Abstract: An image encoding/decoding method and apparatus are provided. An image decoding method according to the present disclosure may include determining whether a prediction mode of a current block is an intra prediction mode based on information on the prediction mode of the current block, determining whether intra sub-partitions (ISP) is available for the current block, when the prediction mode of the current block is an intra prediction mode, decoding an ISP application indicator indicating whether to apply ISP to the current block, when ISP is available for the current block, and generating a prediction block for the current block by applying ISP to the current block, upon determining that ISP applies to the current block based on the ISP application indicator.

公开(公告)号：US20210218996A1

公开(公告)日：2021-07-15

申请号：US17047849

申请日：2019-04-17

Applicant: LG Electronics Inc.

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

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

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：US20210160490A1

公开(公告)日：2021-05-27

申请号：US17168571

申请日：2021-02-05

Applicant: LG ELECTRONICS INC.

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

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

Abstract: Embodiments of the present invention provide a method and apparatus for processing a video signal. A method for decoding an image signal according to an embodiment of the present invention comprises the steps of: for a current block having a width and a height different from each other, determining a modified intra prediction mode from an intra prediction mode, on the basis of a ratio between the width and the height of the current block and the intra prediction mode; determining an inverse non-separable transform set on the basis of the modified intra prediction mode; and applying an inverse non-separable transform matrix selected from the inverse non-separable transform set with respect to the top-left region of the current block, which is determined according to the width and the height of the current block.