US 12,250,384 B2
Encoder, decoder, encoding method, and decoding method using horizontal and vertical gradients for prediction
Jing Ya Li, Singapore (SG); Ru Ling Liao, Singapore (SG); Chong Soon Lim, Singapore (SG); Han Boon Teo, Singapore (SG); Hai Wei Sun, Singapore (SG); Kiyofumi Abe, Osaka (JP); Takahiro Nishi, Nara (JP); and Tadamasa Toma, Osaka (JP)
Assigned to PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA, Torrance, CA (US)
Filed by Panasonic Intellectual Property Corporation of America, Torrance, CA (US)
Filed on Aug. 16, 2023, as Appl. No. 18/234,504.
Application 18/234,504 is a continuation of application No. 17/726,840, filed on Apr. 22, 2022, granted, now 11,778,203.
Application 17/726,840 is a continuation of application No. 17/196,194, filed on Mar. 9, 2021, granted, now 11,350,111, issued on May 31, 2022.
Application 17/196,194 is a continuation of application No. PCT/JP2019/035125, filed on Sep. 6, 2019.
Claims priority of provisional application 62/731,283, filed on Sep. 14, 2018.
Prior Publication US 2023/0396776 A1, Dec. 7, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/117 (2014.01); H04N 19/159 (2014.01); H04N 19/182 (2014.01)
CPC H04N 19/159 (2014.11) [H04N 19/117 (2014.11); H04N 19/182 (2014.11)] 6 Claims
OG exemplary drawing
 
1. An encoder comprising:
a memory; and
a processor connected to the memory and configured to:
determine whether a bi-directional optical flow (BDOF) process is applied;
generate a prediction image based on a first parameter and a second parameter that are derived in the BDOF process; and
encode a current block using the generated prediction image,
wherein
the first parameter is derived based on the following expression:
[Math. 1]
Σ[l,j]ϵΩabs(Ix1+Ix0); and
the second parameter according to the following expression:
[Math. 2]
Σ[l,j]ϵΩ(−sign (Ix1+Ix0)×(I0−I1)),
where:
Ω indicates a set of relative pixel positions;
[i, j] indicates a relative pixel position in the set 22 defined by a horizontal position i and a vertical position j;
Ix0 indicates a horizontal gradient value at a first pixel position in a first gradient image, and Ix1 indicates a horizontal gradient value at the first pixel position in a second gradient image, the first pixel position being determined based on a relative pixel position [i, j], the first gradient image and the second gradient image corresponding to the current block;
I0 indicates a pixel value at the first pixel position in a first interpolated image corresponding to the current block;
I1 indicates a pixel value at the first pixel position in a second interpolated image corresponding to the current block;
the abs function outputs an absolute value of an argument; and
the sign function outputs a sign of an argument.