公开(公告)号：US11516484B2

公开(公告)日：2022-11-29

申请号：US17707000

申请日：2022-03-29

Applicant: LG Electronics Inc.

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

IPC: H04N19/18 ,  H04N19/119 ,  H04N19/129 ,  H04N19/132 ,  H04N19/176 ,  H04N19/186 ,  H04N19/60 ,  H04N19/70 ,  H04N19/96

Abstract: An image decoding method according to the present document comprises: a residual coding step for parsing residual information received in a residual coding level and arranging transform coefficients for a current block according to a predetermined scanning order; a step for deriving residual samples by applying at least one of LFNST or MTS to the transform coefficients; and a step for 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, the LFNST index and the MTS index are signaled in a coding unit level, and the MTS index is signaled immediately after the signaling of the LFNST index.

公开(公告)号：US11503298B2

公开(公告)日：2022-11-15

申请号：US17555881

申请日：2021-12-20

Applicant: LG Electronics Inc.

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

IPC: H04N19/00 ,  H04N19/124 ,  H04N19/625 ,  H04N19/94 ,  H04N19/39

Abstract: An image decoding method according to the present document comprises a step of generating residual samples of a current block on the basis of residual information, wherein the residual information comprises a multiple transform selection (MTS) index and information regarding transform coefficients, the residual samples are generated from transform coefficients according to the information regarding the transform coefficients by using a transform kernel set, the transform kernel set is determined by the MTS index from among transform kernel set candidates, at least one of bins of a bin string of the MTS index is derived on the basis of context coding, the context coding is performed based on a value of a context index with respect to the MTS index.

公开(公告)号：US11483589B2

公开(公告)日：2022-10-25

申请号：US17394734

申请日：2021-08-05

Applicant: LG Electronics Inc.

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Seunghwan Kim

IPC: H04N11/02 ,  H04N19/61 ,  H04N19/119 ,  H04N19/124 ,  H04N19/132 ,  H04N19/159 ,  H04N19/176 ,  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 non-separable quadratic transform; deriving transform coefficients by inversely quantizing the quantized transform coefficient; deriving corrected transform coefficients on the basis of a transform kernel matrix in a predetermined transform set indicated by the transform index; and deriving residual samples for the target block on the basis of inverse linear transform for the corrected transform coefficients, wherein when the target block is divided into a predetermined number of sub-blocks and is coded by intra prediction, the corrected transform coefficients are derived in units of the sub-blocks, and the transform index is received for the target block.

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：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：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：US11122290B2

公开(公告)日：2021-09-14

申请号：US16773958

申请日：2020-01-27

Applicant: LG Electronics Inc.

Inventor： Hyeongmoon Jang ,  Eunyong Son ,  Moonmo Koo ,  Seungwook Park ,  Yongjoon Jeon

IPC: H04N19/56 ,  H04N19/176 ,  H04N19/124 ,  H04N19/503 ,  H04N19/105 ,  H04N19/70 ,  H04N19/182 ,  H04N19/513 ,  H04N19/66 ,  H04N19/91

Abstract: A video decoding method performed by a decoding apparatus includes the steps of: deriving control points (CP) for a current block; acquiring movement vectors for the CPs; deriving a sample unit movement vector in the current block on the basis of the acquired movement vectors; and deriving a prediction sample for the current block on the basis of the sample unit movement vector. According to the present invention, it is possible to effectively perform, through sample unit motion vectors, inter-prediction not only in a case where an image in the current block is plane-shifted but also in a case where there are various image distortions.

公开(公告)号：US20210203969A1

公开(公告)日：2021-07-01

申请号：US17138722

申请日：2020-12-30

Applicant: LG ELECTRONICS INC.

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

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

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.

公开(公告)号：US11012702B2

公开(公告)日：2021-05-18

申请号：US16898117

申请日：2020-06-10

Applicant: LG ELECTRONICS INC.

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

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

Abstract: A method and a device for processing a video signal are disclosed. In particular, a method for decoding a video signal includes parsing a first syntax element indicating a primary transform kernel applied to a primary transform of a current block; determining whether a secondary transform is applicable to the current block based on the first syntax element; if the secondary transform is applicable to the current block, parsing a second syntax element indicating a secondary transform kernel applied to a secondary transform of the current block; deriving a secondary inverse-transformed block, by performing a secondary inverse-transform for a top-left specific region of the current block using a secondary transform kernel indicated by the second syntax element; and deriving a residual block of the current block, by performing a primary inverse-transform for the secondary inverse-transformed block using a primary transform kernel indicated by the first syntax element.

公开(公告)号：US10979736B2

公开(公告)日：2021-04-13

申请号：US16620438

申请日：2018-06-08

Applicant: LG ELECTRONICS INC. ,  INDUSTRY-ACADEMIC COOPERATION FOUNDATION, CHOSUN UNIVERSITY

Inventor： Moonmo Koo ,  Jaehyun Lim ,  Bumshik Lee

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

Abstract: The present disclosure provides a method for processing a video signal by using a linear relationship between transform types, the method comprising the steps of: determining a transform group on the basis of a prediction mode of a current block; parsing a transform combination index from the video signal, wherein the transform combination index indicates one of a plurality of transform combinations in the transform group; deriving a transform combination corresponding to the transform combination index, wherein the transform combination includes a horizontal transform and a vertical transform and includes DST-1 or DCT-5; performing inverse transform of the current block on the basis of the transform combination; and reconstructing the video signal by using the inverse-transformed current block.