US 11,943,445 B2
Image coding method and device therefor
Moonmo Koo, Seoul (KR); Jie Zhao, Seoul (KR); Hyeongmoon Jang, Seoul (KR); Seunghwan Kim, Seoul (KR); and Jaehyun Lim, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Filed by LG Electronics Inc., Seoul (KR)
Filed on Nov. 11, 2022, as Appl. No. 17/985,507.
Application 17/985,507 is a continuation of application No. PCT/KR2021/005877, filed on May 11, 2021.
Claims priority of provisional application 63/035,854, filed on Jun. 8, 2020.
Claims priority of provisional application 63/025,149, filed on May 14, 2020.
Claims priority of provisional application 63/023,824, filed on May 12, 2020.
Claims priority of provisional application 63/022,595, filed on May 11, 2020.
Prior Publication US 2023/0078305 A1, Mar. 16, 2023
Int. Cl. H04N 11/02 (2006.01); H04N 19/132 (2014.01); H04N 19/176 (2014.01); H04N 19/18 (2014.01); H04N 19/186 (2014.01); H04N 19/46 (2014.01)
CPC H04N 19/132 (2014.11) [H04N 19/176 (2014.11); H04N 19/18 (2014.11); H04N 19/186 (2014.11); H04N 19/46 (2014.11)] 6 Claims
OG exemplary drawing
 
1. An image decoding method performed by a decoding apparatus, the method comprising:
receiving image information comprising residual information and an LFNST index from a bitstream;
deriving transform coefficients by performing dequantization based on the residual information;
deriving a flag variable array related to whether an LFNST is applied to a current block based on the LFNST index; and
performing the LFNST based on the flag variable array and the transform coefficients,
wherein the flag variable array is defined as a one-dimensional array,
wherein flag variables included in the flag variable array are derived for each color component of the current block,
wherein the flag variable array includes a first flag variable for a luma component, a second flag variable for a Cb component and a third flag variable for a Cr component,
wherein the first flag variable is set to 1 and the second flag variable and the third flag variable are set to 0, based on a tree type of the current block being a single tree and a value of the LFNST index being greater than 0,
wherein the first flag variable is set to 1 based on a tree type of the current block being a dual tree luma and the value of the LFNST index being greater than 0,
wherein the second flag variable and the third flag variable are set to 1 based on a tree type of the current block being a dual tree chroma and a value of the LFNST index being greater than 0,
wherein the dequantization is performed based on a scaling list, and
wherein whether to apply the scaling list for the each color component of the current block is determined based on a value of a flag variable allocated for the each color component in the flag variable array.