US 11,943,451 B2
Chroma block prediction method and apparatus
Xiang Ma, Shenzhen (CN); Fan Mu, Shenzhen (CN); Yin Zhao, Hangzhou (CN); and Haitao Yang, Shenzhen (CN)
Assigned to HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
Filed by HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
Filed on Jul. 1, 2021, as Appl. No. 17/365,372.
Application 17/365,372 is a continuation of application No. PCT/CN2019/124399, filed on Dec. 10, 2019.
Claims priority of application No. 201910005667.3 (CN), filed on Jan. 3, 2019.
Prior Publication US 2021/0329261 A1, Oct. 21, 2021
Int. Cl. H04N 19/159 (2014.01); H04N 19/132 (2014.01); H04N 19/176 (2014.01)
CPC H04N 19/159 (2014.11) [H04N 19/132 (2014.11); H04N 19/176 (2014.11)] 20 Claims
OG exemplary drawing
 
1. A chroma block prediction method, comprising:
obtaining chroma values of chroma samples;
obtaining, based on neighboring samples of a luma block corresponding to a chroma block, luma values of luma samples;
obtaining, from the obtained luma values, a first luma set and a second luma set;
grouping chroma values of chroma samples corresponding to luma samples associated with luma values in the first luma set into a first chroma set, and grouping chroma values of chroma samples corresponding to luma samples associated with luma values in the second luma set into a second chroma set;
determining a scaling coefficient in a linear model corresponding to the chroma block based on an average value of the luma values in the first luma set, an average value of the luma values in the second luma set, an average value of the chroma values in the first chroma set, and an average value of the chroma values in the second chroma set;
determining, based on the scaling coefficient, an offset factor in the linear model corresponding to the chroma block; and
determining prediction information of the chroma block based on the scaling coefficient, the offset factor, and luma reconstruction information corresponding to the chroma block, wherein the luma reconstruction information corresponding to the chroma block comprises downsampling information of a luma reconstructed block corresponding to the chroma block;
wherein the obtaining, from the obtained luma values, a first luma set and a second luma set comprises:
sorting the luma values of the luma samples corresponding to the chroma samples at preset locations in ascending order, to obtain a first luma value queue; and grouping luma values of a first half part in the first luma value queue into the first luma set, and grouping luma values of a second half part in the first luma value queue into the second luma set; or
sorting the luma values of the luma samples corresponding to the chroma samples at the preset locations in descending order, to obtain a second luma value queue; and grouping luma values of a second half part in the second luma value queue into the first luma set, and grouping luma values of a first half part in the second luma value queue into the second luma set.