US 11,870,992 B2
Encoder that determines an intra prediction mode used for a current block and performs quantization on first transform coefficients or second transform coefficients based on whether a primary transform basis is included in predetermined transform bases
Ryuichi Kanoh, Osaka (JP); Tadamasa Toma, Osaka (JP); Kiyofumi Abe, Osaka (JP); and Takahiro Nishi, Nara (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 Apr. 29, 2022, as Appl. No. 17/732,693.
Application 17/732,693 is a continuation of application No. 16/728,784, filed on Dec. 27, 2019, abandoned.
Application 16/728,784 is a continuation of application No. PCT/JP2018/024076, filed on Jun. 26, 2018.
Claims priority of provisional application 62/528,193, filed on Jul. 3, 2017.
Prior Publication US 2022/0264093 A1, Aug. 18, 2022
Int. Cl. H04N 19/12 (2014.01); H04N 19/61 (2014.01); H04N 19/154 (2014.01); H04N 19/157 (2014.01)
CPC H04N 19/12 (2014.11) [H04N 19/154 (2014.11); H04N 19/157 (2014.11); H04N 19/61 (2014.11)] 2 Claims
OG exemplary drawing
 
1. An encoder comprising:
a processor; and
memory,
wherein, using the memory, the processor:
derives a residual signal of a current block by subtracting a prediction signal from an input signal;
determines an intra prediction mode used for the current block;
performs a primary transform on the residual signal, using a primary transform basis, to generate first transform coefficients;
when the primary transform basis is different from predetermined transform bases, performs a quantization on the first transform coefficients without performing a secondary transform; and
when the primary transform basis is included in the predetermined transform bases, (i) performs a secondary transform on the first transform coefficients, using a secondary transform basis selected from among one or more candidate secondary transform bases associated with the intra prediction mode, to generate second transform coefficients, and (ii) performs a quantization on the second transform coefficients, and
wherein the secondary transform is performed on a part of the first transform coefficients generated by the primary transform.