US 12,267,509 B2
Cross component determination of chroma and luma components of video data
Yi-Wen Chen, Beijing (CN); Xiaoyu Xiu, Beijing (CN); Tsung-Chuan Ma, Beijing (CN); Hong-Jheng Jhu, Beijing (CN); Xianglin Wang, Beijing (CN); and Bing Yu, Beijing (CN)
Assigned to BEIJING DAJIA INTERNET INFORMATION TECHNOLOGY CO., LTD., Beijing (CN)
Filed by BEIJING DAJIA INTERNET INFORMATION TECHNOLOGY CO., LTD., Beijing (CN)
Filed on Jun. 30, 2022, as Appl. No. 17/854,455.
Application 17/854,455 is a continuation of application No. PCT/US2020/067356, filed on Dec. 29, 2020.
Prior Publication US 2022/0337847 A1, Oct. 20, 2022
Int. Cl. H04N 19/186 (2014.01); H04N 19/132 (2014.01); H04N 19/167 (2014.01); H04N 19/176 (2014.01); H04N 19/182 (2014.01); H04N 19/196 (2014.01); H04N 19/70 (2014.01)
CPC H04N 19/186 (2014.11) [H04N 19/132 (2014.11); H04N 19/167 (2014.11); H04N 19/176 (2014.11); H04N 19/182 (2014.11); H04N 19/197 (2014.11); H04N 19/70 (2014.11)] 16 Claims
OG exemplary drawing
 
1. A method for decoding video data, comprising:
obtaining, from a bitstream, a plurality of luma samples for a plurality of pixels in a video frame, wherein the plurality of pixels belong to a coding block and include a boundary pixel located inside the coding block, wherein the boundary pixel is immediately adjacent to a boundary of the coding block;
determining that one or more neighboring pixels of the boundary pixel are not available, each of the one or more neighboring pixels being outside the coding block;
assigning a respective luma sample corresponding to the boundary pixel to a luma sample corresponding to each of the one or more neighboring pixels;
determining a boundary luma sample based, at least, on the luma samples of the one or more neighboring pixels and the boundary pixel according to a predefined luma interpolation scheme; and
obtaining, from the bitstream, a second plurality of luma samples and a second plurality of chroma samples;
determining an alternative plurality of luma samples having a same resolution as the second plurality of chroma samples according to the predefined luma interpolation scheme;
deriving a first parameter α and a second parameter β for a linear mapping model by using the alternative plurality of luma samples and the second plurality of chroma samples, comprising:
identifying two largest luma samples among the alternative plurality of luma samples;
identifying two smallest luma samples among the alternative plurality of luma samples;
determining a first luma value based on the two largest luma samples;
determining a second luma value based on the two smallest luma samples;
identifying two first chroma samples among the second plurality of chroma samples associated with the two largest luma samples;
identifying two second chroma samples among the second plurality of chroma samples associated with the two smallest luma samples;
determining a first chroma value corresponding to the first luma value based on two first chroma values;
determining a second chroma value corresponding to the second luma value based on two second chroma values; and
deriving the linear mapping model between chroma values and luma values based on the first and second luma values and the first and second chroma values; and
determining a boundary chroma sample from the boundary luma sample according to the linear mapping model.