US 12,452,437 B1
Fast parameter search for chroma from luma intra prediction in video coding
Yi Guo, Hangzhou (CN); Zhichu He, Hangzhou (CN); Rui Li, Hangzhou (CN); Bo Ling, Saratoga, CA (US); Jing Wu, Hangzhou (CN); Minxia Yang, Hangzhou (CN); Shiyan Zhang, Hangzhou (CN); and Yichen Zhang, Hangzhou (CN)
Assigned to Zoom Communications, Inc., San Jose, CA (US)
Filed by Zoom Video Communications, Inc., San Jose, CA (US)
Filed on Jul. 19, 2023, as Appl. No. 18/223,893.
Int. Cl. H04N 19/186 (2014.01); H04N 19/147 (2014.01); H04N 19/159 (2014.01); H04N 19/176 (2014.01)
CPC H04N 19/186 (2014.11) [H04N 19/147 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11)] 20 Claims
OG exemplary drawing
 
1. A method comprising:
determining a value of a parameter of a linear chroma from luma (CFL) predictor for a coding block of a frame of a video, the parameter of the linear CFL having a value range, the determining comprising:
determining a search range within the value range, the search range being divided into three portions by a starting value within the search range, a first portion containing a first set of values on one side of the starting value within the search range, a second portion containing a second set of values on the other side of the starting value within the search range, and a third portion containing the starting value;
determining an initial cost value of a cost function defined for the coding block by setting the parameter to the starting value;
determining a first cost value of the cost function by setting the parameter to a first value within the first set of values;
determining a second cost value of the cost function by setting the parameter to a second value within the second set of values; and
determining the value of the parameter as one of the starting value, the first value, or the second value that corresponds to a lowest cost value among the initial cost value, the first cost value, and the second cost value; and
encoding the coding block of the frame into a bitstream representing the video using the CFL predictor with the determined value of the parameter.