US 12,284,369 B2
Luma mapping-based video or image coding
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. 11, 2024, as Appl. No. 18/410,371.
Application 18/410,371 is a continuation of application No. 18/070,095, filed on Nov. 28, 2022, granted, now 11,924,447.
Application 18/070,095 is a continuation of application No. 17/566,902, filed on Dec. 31, 2021, granted, now 11,563,956, issued on Jan. 24, 2023.
Application 17/566,902 is a continuation of application No. PCT/KR2020/008806, filed on Jul. 6, 2020.
Claims priority of provisional application 62/871,071, filed on Jul. 5, 2019.
Prior Publication US 2024/0155138 A1, May 9, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/46 (2014.01); H04N 19/157 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01)
CPC H04N 19/186 (2014.11) [H04N 19/157 (2014.11); H04N 19/176 (2014.11); H04N 19/46 (2014.11)] 3 Claims
OG exemplary drawing
 
1. A decoding apparatus for image decoding, the decoding apparatus comprising:
a memory; and
at least one processor connected to the memory, the at least one processor configured to:
obtain image information including prediction related information, residual information and information on luma mapping with chroma scaling (LMCS) data from a bitstream;
generate prediction chroma samples for a current block in a current picture based on the prediction related information;
generate residual chroma samples for the current block based on the residual information;
derive LMCS codewords based on the information on the LMCS data;
generate scaled residual chroma samples based on the residual chroma samples and the LMCS codewords; and
generate reconstructed chroma samples for the current block based on the prediction chroma samples and the scaled residual chroma samples,
wherein the image information includes a sequence parameter set (SPS), information on an absolute value of a chroma residual scaling delta value and information on a sign of the chroma residual scaling delta value,
wherein the SPS includes an LMCS enabled flag representing whether an LMCS data field is enabled,
wherein the information on the LMCS data includes information on the LMCS codewords,
wherein the LMCS codewords are derived based on the information on the LMCS codewords,
wherein the information on the sign of the chroma residual scaling delta value is included in the image information based on the information on the absolute value of the chroma residual scaling delta value,
wherein a chroma residual scaling factor is derived based on 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, and
wherein the scaled residual chroma samples are derived based on the chroma residual scaling factor.