US 11,943,434 B2
Method and device for image decoding on basis of CCLM prediction in image coding system
Jangwon Choi, Seoul (KR); Seunghwan Kim, Seoul (KR); and Jin Heo, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Filed by LG ELECTRONICS INC., Seoul (KR)
Filed on Feb. 9, 2022, as Appl. No. 17/667,957.
Application 17/667,957 is a continuation of application No. 17/276,438, granted, now 11,290,713, previously published as PCT/KR2019/012195, filed on Sep. 20, 2019.
Claims priority of provisional application 62/737,885, filed on Sep. 27, 2018.
Claims priority of provisional application 62/734,239, filed on Sep. 20, 2018.
Prior Publication US 2022/0174275 A1, Jun. 2, 2022
Int. Cl. H04N 19/11 (2014.01); H04N 19/105 (2014.01); H04N 19/132 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01); H04N 19/46 (2014.01); H04N 19/593 (2014.01)
CPC H04N 19/11 (2014.11) [H04N 19/105 (2014.11); H04N 19/132 (2014.11); H04N 19/176 (2014.11); H04N 19/186 (2014.11); H04N 19/46 (2014.11); H04N 19/593 (2014.11)] 11 Claims
OG exemplary drawing
 
1. An image decoding method performed by a decoding apparatus, the image decoding method comprising:
obtaining prediction related information for a current chroma block;
deriving a cross-component linear model (CCLM) mode as an intra prediction mode of the current chroma block based on the prediction related information;
deriving a specific value for the current chroma block;
deriving specific top neighboring chroma samples and specific left neighboring chroma samples of the current chroma block based on a width and a height of the current chroma block and the specific value;
deriving CCLM parameters based on the specific top neighboring chroma samples and the specific left neighboring chroma samples;
deriving prediction samples for the current chroma block based on the CCLM parameters; and
generating reconstructed samples for the current chroma block based on the prediction samples,
wherein the derived specific value is 2,
wherein based on the width and the height being greater than or equal to the specific value, top neighboring chroma samples of specific top positions among top neighboring chroma samples of the current chroma block are selected as the specific top neighboring chroma samples,
wherein the specific top positions are derived based on the number of the specific top neighboring chroma samples and the width of the current chroma block,
wherein based on the width and the height being greater than or equal to the specific value, left neighboring chroma samples of specific left positions among left neighboring chroma samples of the current chroma block are selected as the specific left neighboring chroma samples, and
wherein the specific left positions are derived based on the number of the specific left neighboring chroma samples and the height of the current chroma block.