US 12,407,824 B2
Selecting downsampling filters for chroma from luma prediction
Jing Ye, San Jose, CA (US); Xin Zhao, San Jose, CA (US); Liang Zhao, Sunnyvale, CA (US); and Shan Liu, San Jose, CA (US)
Assigned to Tencent America LLC, Palo Alto, CA (US)
Filed by Tencent America LLC, Palo Alto, CA (US)
Filed on Nov. 22, 2022, as Appl. No. 17/992,282.
Claims priority of provisional application 63/403,635, filed on Sep. 2, 2022.
Prior Publication US 2024/0080443 A1, Mar. 7, 2024
Int. Cl. H04N 19/117 (2014.01); H04N 19/11 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01)
CPC H04N 19/117 (2014.11) [H04N 19/11 (2014.11); H04N 19/176 (2014.11); H04N 19/186 (2014.11)] 13 Claims
OG exemplary drawing
 
1. A method for video processing, the method comprising:
receiving an input chroma block from a video sequence;
determining that the input chroma block is to be predicted in a Chroma from Luma (CfL) prediction mode for the video sequence;
applying a plurality of downsampling filters to obtain a plurality of sets of downsampled luma samples corresponding to the input chroma block, respectively;
iteratively predicting the input chroma block in the CfL prediction mode based on each of the plurality of sets of downsampled luma samples;
calculating a plurality of error scores for the iteratively predicting, each of the plurality of error scores corresponding to a respective one of the plurality of downsampling filters;
biasing one of the plurality of error scores to increase a likelihood that a downsampling filter corresponding to the one of the plurality of error scores is selected;
selecting a target downsampling filter from the plurality of downsampling filters based on the plurality of error scores with the biasing; and
encoding the input chroma block in the CfL prediction mode by applying the selected target downsampling filter.