US 12,244,830 B2
Video or image coding based on mapping of luma samples and scaling of chroma samples
Jie Zhao, Seoul (KR); and Seunghwan Kim, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Filed by LG ELECTRONICS INC., Seoul (KR)
Filed on Jan. 16, 2024, as Appl. No. 18/413,610.
Application 18/413,610 is a continuation of application No. 18/139,479, filed on Apr. 26, 2023, granted, now 11,930,192.
Application 18/139,479 is a continuation of application No. 17/566,971, filed on Dec. 31, 2021, granted, now 11,695,942, issued on Jul. 4, 2023.
Application 17/566,971 is a continuation of application No. PCT/KR2020/008799, filed on Jul. 6, 2020.
Claims priority of provisional application 62/871,070, filed on Jul. 5, 2019.
Prior Publication US 2024/0163460 A1, May 16, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/186 (2014.01); H04N 19/117 (2014.01); H04N 19/132 (2014.01); H04N 19/159 (2014.01); H04N 19/169 (2014.01); H04N 19/172 (2014.01); H04N 19/176 (2014.01); H04N 19/70 (2014.01); H04N 19/96 (2014.01)
CPC H04N 19/186 (2014.11) [H04N 19/132 (2014.11); H04N 19/159 (2014.11); H04N 19/172 (2014.11); H04N 19/176 (2014.11); H04N 19/1887 (2014.11); H04N 19/70 (2014.11); H04N 19/96 (2014.11); H04N 19/117 (2014.11)] 3 Claims
OG exemplary drawing
 
1. An image decoding method performed by a decoding apparatus, the image decoding method comprising:
obtaining image information including luma mapping with chroma scaling (LMCS) related information, prediction related information, and residual information from a bitstream;
deriving LMCS codewords based on the LMCS related information;
determining an inter prediction mode as a prediction mode of a current block in a current picture based on the prediction related information;
generating prediction chroma samples for the current block based on the prediction mode;
deriving transform coefficients for the current block based on the residual information;
generating residual chroma samples for the current block based on the transform coefficients;
deriving a chroma residual scaling factor for luma dependent chroma residual scaling based on the LMCS codewords and luma samples; and
generating reconstructed chroma samples for the current block based on the chroma residual scaling factor,
wherein the LMCS related information includes information on bins and information on the LMCS codewords,
wherein a minimum bin index and a maximum bin index are derived based on the information on the bins,
wherein the LMCS codewords are derived based on the information on the LMCS codewords,
wherein the image information includes information on an absolute value of a chroma residual scaling delta value and information on a sign of the chroma residual scaling delta value, and
wherein the chroma residual scaling factor is derived based on the LMCS codewords, the information on the absolute value of the chroma residual scaling delta value and the information on the sign of the chroma residual scaling delta value.