US 12,382,052 B2
Chroma sample weight derivation for geometric partition mode
Semih Esenlik, Munich (DE); Max Blaeser, Aachen (DE); Zhijie Zhao, Shenzhen (CN); Han Gao, Munich (DE); Anand Meher Kotra, Munich (DE); Biao Wang, Munich (DE); and Elena Alexandrovna Alshina, Munich (DE)
Assigned to HUAWEI TECHNOLOGIES CO., LTD., Shenzhen (CN)
Filed by HUAWEI TECHNOLOGIES CO.,LTD., Guangdong (CN)
Filed on Sep. 30, 2021, as Appl. No. 17/489,793.
Application 17/489,793 is a continuation of application No. PCT/CN2020/097147, filed on Jun. 19, 2020.
Claims priority of application No. PCT/EP2019/066516 (WO), filed on Jun. 21, 2019.
Prior Publication US 2022/0021883 A1, Jan. 20, 2022
Int. Cl. H04N 19/132 (2014.01); H04N 19/105 (2014.01); H04N 19/159 (2014.01); H04N 19/176 (2014.01); H04N 19/186 (2014.01)
CPC H04N 19/132 (2014.11) [H04N 19/105 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/186 (2014.11)] 15 Claims
OG exemplary drawing
 
1. A method of coding implemented by a decoding device, comprising:
obtaining a value of a parameter for a current block, the value of the parameter indicating a partition mode for the current block;
obtaining a first prediction mode for the current block;
obtaining a second prediction mode for the current block;
generating a first prediction value for a chroma sample in the current block according to the first prediction mode;
generating a second prediction value for a chroma sample in the current block according to the second prediction mode;
obtaining a combined prediction value by combining the first prediction value and the second prediction value;
obtaining a weight value for a luma sample by calculating the weight value for the luma sample; and obtaining a first weight value for a chroma sample by calculating the first weight value for the chroma sample;
obtaining a combined prediction value for the chroma sample in the current block, according to the first prediction value for the chroma sample and the first weight value for the chroma sample; and
wherein the combined prediction value is obtained by combining the first prediction value and the second prediction value according to a blending operation, the blending operation is implemented using a function of a sample distance sample_dist as input and sample Weight1 as output,
wherein said sample_dist function is a division or multiplication with a constant number operation, a right shifting a constant amount operation, a taking the absolute value or a clipping operation or a combination of those, and wherein sample_dist=((x<<1)+1)*Dis[angleIdx1]+ ((y<<1)+1))*Dis[angleIdx2]−offset (distanceIdx), and wherein angleIdx1 and angleIdx2 represent quantized trigonometric parameters of a separation line and angleIdx2 is equal to a remainder of a variable (displacementX) plus 8 and divided by 32, x and y are the −x and −y coordinates of a sample with respect to top-left sample of a coding block, offset (distanceIdx) is an offset value, which is a function of an index value (distanceIdx), and Dis[ ] is a lookup table describing the change in the sample distance with respect to a unit increase in the x or y directions, and wherein sample Weight1=Clip3(0, 8, f (sample_dist)), wherein f( ) 1s a division/addition/multiplication with a constant number operation, a right shifting with a constant amount operation, taking the absolute value operation or a clipping operation or a combination of those,
wherein sample Weight1=Clip3(0, 8, sample_dist*K+Clip3(0, 8, sample_dist+4)), sample_dist represents a distance of the luma sample to a separation line of the current block, and K is an integer with a value greater than 0.