公开(公告)号：US11425421B1

公开(公告)日：2022-08-23

申请号：US17337148

申请日：2021-06-02

Applicant: LG Electronics Inc.

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

IPC: H04N19/00 ,  H04N19/61 ,  H04N19/18 ,  H04N19/124 ,  H04N19/132 ,  H04N19/129 ,  H04N19/159 ,  H04N19/11 ,  H04N19/122 ,  H04N19/176

Abstract: An image decoding method according to the present specification comprises the steps of: deriving transform coefficients through inverse quantization on the basis of quantized transform coefficient for a target block; deriving modified transform coefficients on the basis of 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 the step of deriving the modified transform coefficients is characterized in deriving 16 modified transform coefficients by applying a transform kernel matrix to 8 transform coefficients in a 4×4 region of the target block.

公开(公告)号：US11412242B2

公开(公告)日：2022-08-09

申请号：US17266407

申请日：2019-08-08

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/44 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  H04N19/625 ,  H04N19/70

Abstract: The present invention relates to a video signal decoding method based on a Multiple Transform Selection (MTS). The method may comprise the steps of: parsing a first syntax element representing whether MTS applies to the inverse transformation of a current block, wherein the MTS represents a transform mode which uses a transform type other than a default transform type predefined for the current block; by performing inverse quantization on the current block, deriving an inverse-quantized transform coefficient array having the width and the height of the current block; determining, on the basis of the first syntax element, a vertical transform type applying to the vertical direction of the current block, and a horizontal transform type applying to the horizontal direction of the current block; and, by performing inverse transformation on the inverse-quantized transform coefficient array by using the vertical transform type and the horizontal transform type, deriving a residual sample array having the width and the height of the current block.

公开(公告)号：US11356702B2

公开(公告)日：2022-06-07

申请号：US15734806

申请日：2019-06-07

Applicant: LG ELECTRONICS INC.

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

IPC: H04N19/61 ,  H04N19/11 ,  H04N19/176 ,  H04N19/593

Abstract: The present disclosure, in a method of decoding a video signal, provides a method including checking whether a transform skip is applied to a current block; acquiring a transform index indicating transform types applied to a horizontal direction and a vertical direction of the current block from among a plurality of predefined transform types from the video signal when the transform skip is not applied to the current block; and performing an inverse primary transform on the current block using the transform types indicated by the transform index, wherein the transform types applied to the horizontal direction and the vertical direction of the current block are determined from among transform types defined according to an intra prediction mode of the current block based on the transform index.

公开(公告)号：US20220132146A1

公开(公告)日：2022-04-28

申请号：US17568322

申请日：2022-01-04

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：US11284082B2

公开(公告)日：2022-03-22

申请号：US17349215

申请日：2021-06-16

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Seunghwan Kim ,  Jaehyun Lim

IPC: H04N19/132 ,  H04N19/30 ,  H04N19/176 ,  H04N19/159 ,  H04N19/18 ,  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：US11277640B2

公开(公告)日：2022-03-15

申请号：US16781416

申请日：2020-02-04

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo

IPC: H04N19/61 ,  H04N19/12 ,  H04N19/176 ,  H04N19/625 ,  H04N19/122

Abstract: The present disclosure relates to a method for decoding a video signal based on adaptive multiple transforms (AMT). The method includes: obtaining an AMT index from the video signal, where the AMT index indicates any one of a plurality of transform combinations in a transform configuration group, and the transform configuration group includes discrete sine transform type 7 (DST7) and discrete cosine transform type 8 (DCT8): deriving a transform combination corresponding to the AMT index, where the transform combination includes a horizontal transform and a vertical transform, and at least one of the DST-7 or the DCT-8: performing an inverse transform on a current block on the basis of the transform combination; and restoring the video signal by using the inversely transformed current block. The AMT represents a transform scheme that is performed based on a transform combination adaptively selected from a plurality of transform combinations.

公开(公告)号：US20220060697A1

公开(公告)日：2022-02-24

申请号：US17476696

申请日：2021-09-16

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.

公开(公告)号：US11245894B2

公开(公告)日：2022-02-08

申请号：US16897681

申请日：2020-06-10

Applicant: LG Electronics Inc.

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

IPC: H04N19/12 ,  H04N19/593 ,  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：US20210360254A1

公开(公告)日：2021-11-18

申请号：US17385628

申请日：2021-07-26

Applicant: LG ELECTRONICS INC.

Inventor： Mehdi SALEHIFAR ,  Seunghwan Kim ,  Moonmo Koo ,  Jaehyun Lim ,  Seethal Palurl

IPC: H04N19/132 ,  H04N19/105 ,  H04N19/176 ,  H04N19/18

Abstract: A method for decoding an image by a decoding device according to the present invention comprises the steps of: deriving, from a bit stream, transform coefficients of a block to be decoded; deriving residual samples of the block to be decoded, on the basis of a selective transform of the transform coefficients; and generating a reconstructed picture on the basis of the residual samples of the block to be decoded and prediction samples of the block to be decoded, wherein the selective transform is performed on the basis of a modified transform matrix, the modified transform matrix comprises a matrix including a modified basis vector, and the modified basis vector contains a certain number of elements selected from N elements.

公开(公告)号：US11025957B2

公开(公告)日：2021-06-01

申请号：US15886548

申请日：2018-02-01

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Onur Guleryuz

IPC: H04N19/63 ,  H04N19/60 ,  H04N19/91 ,  H04N19/124 ,  G06F17/14

Abstract: A method for performing a transform by using Layered Givens Transform may include: deriving at least one rotation layer, a first permutation layer and a second permutation layer based on a given transform matrix H and an error parameter; obtaining a Layered Givens Transform (LGT) coefficient based on the rotation layer, the first permutation layer and the second permutation layer; and performing quantization and entropy encoding with respect to the LGT coefficient, the first permutation layer and the second permutation layer may include a permutation matrix obtained by permuting a row of an identity matrix, and the LGT coefficient may be obtained by sequentially applying the first permutation layer, the rotation layer and the second permutation layer respectively.