US 12,143,583 B2
Encoder, decoder, encoding method, and decoding method
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 Oct. 15, 2020, as Appl. No. 17/071,470.
Application 17/071,470 is a continuation of application No. PCT/JP2019/022788, filed on Jun. 7, 2019.
Claims priority of provisional application 62/697,605, filed on Jul. 13, 2018.
Claims priority of provisional application 62/683,286, filed on Jun. 11, 2018.
Prior Publication US 2021/0037243 A1, Feb. 4, 2021
Int. Cl. H04N 19/12 (2014.01); H04N 19/126 (2014.01); H04N 19/159 (2014.01); H04N 19/176 (2014.01)
CPC H04N 19/12 (2014.11) [H04N 19/126 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11)] 2 Claims
OG exemplary drawing
 
1. An encoder, comprising:
circuitry; and
memory, wherein
using the memory, the circuitry:
applies a first transform to a residual signal of a current block; and
applies a second transform to a result of the first transform, the second transform being a non-separable transform, wherein
(i) when a size of the current block is a first block size, the second transform is applied to a first sub-block having a first sub-block size in the current block using a transform scheme of the second transform is selected from a first group of candidates,
(ii) when the size of the current block is a second block size different from the first block size, the second transform is applied to a second sub-block having the first sub-block size in the current block using the transform scheme of the second transform is selected from a second group of candidates,
the first group of candidates includes a first transform scheme which generates a first number of transform coefficients using a first transform matrix, and
the second group of candidates includes a second transform scheme which generates a second number of transform coefficients using the first transform matrix, the first number is smaller than the second number.