US 12,069,243 B2
Video encoding and decoding using luma mapping chroma scaling
Yong Jo Ahn, Seoul (KR); Jong Seok Lee, Seoul (KR); Seung Wook Park, Yongin-si (KR); and Wha Pyeong Lim, Hwaseong-si (KR)
Assigned to HYUNDAI MOTOR COMPANY, Seoul (KR); KIA CORPORATION, Seoul (KR); and DIGITALINSIGHTS INC., Seoul (KR)
Appl. No. 17/924,898
Filed by HYUNDAI MOTOR COMPANY, Seoul (KR); KIA CORPORATION, Seoul (KR); and DIGITALINSIGHTS INC., Seoul (KR)
PCT Filed Jun. 11, 2021, PCT No. PCT/KR2021/007321
§ 371(c)(1), (2) Date Nov. 11, 2022,
PCT Pub. No. WO2021/251787, PCT Pub. Date Dec. 16, 2021.
Claims priority of application No. 10-2020-0071026 (KR), filed on Jun. 11, 2020; application No. 10-2020-0071028 (KR), filed on Jun. 11, 2020; and application No. 10-2021-0075628 (KR), filed on Jun. 10, 2021.
Prior Publication US 2023/0199169 A1, Jun. 22, 2023
Int. Cl. H04N 19/44 (2014.01); H04N 19/105 (2014.01); H04N 19/132 (2014.01); H04N 19/159 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01); H04N 19/46 (2014.01)
CPC H04N 19/105 (2014.11) [H04N 19/132 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/186 (2014.11); H04N 19/46 (2014.11)] 16 Claims
OG exemplary drawing
 
1. A video decoding method for performing intra prediction for a current block, which is performed by a video decoding apparatus, the method comprising:
obtaining luma mapping chroma scaling (LMCS) parameters, a first flag indicating whether LMCS is activated, and a second flag indicating whether chroma residual scaling is activated, from a bitstream, wherein the LMCS converts the luma signals between an original area and a mapping area of a luma signal;
generating luma residual signals and scaled chroma residual signals from the bitstream;
generating a luma mapping function of converting a dynamic area of the luma signals by using the LMCS parameters when the first flag is activated, wherein the luma mapping function indicates a first function of converting the luma signals into the mapping area or a second function of inversely converting the mapped luma signals into the original area;
generating luma reference samples for the current block by using the luma mapping function when neighboring restoration samples of the current block are not available;
generating luma predicted samples by performing intra prediction for the current block based on the luma reference samples; and
generating luma restoration samples by adding the luma predicted samples and the luma residual signals.