# US 12,120,349 B2 · Encoder, decoder, encoding method, and decoding method

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- Number: US 12,120,349 B2
- Document ID: US12120349B2
- Status: Granted
- Kind: B2
- Application number: 17/889,580
- Filed: 2022-08-17
- Published: 2022-12-08
- Granted: 2024-10-15
- Earliest claimed: 2017-10-06
- Assignees: Panasonic Intellectual Property Corporation of America
- Applicants: Panasonic Intellectual Property Corporation of America
- Inventors: Ryuichi Kanoh; Tadamasa Toma; Kiyofumi Abe; Takahiro Nishi; Masato Ohkawa; Hideo Saitou
- Web page: https://patentgrep.com/patent/US12120349B2

## CPC

- H04N 19/12: Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
- H04N 19/60: using transform coding
- H04N 19/124: Quantisation
- H04N 19/136: Incoming video signal characteristics or properties
- H04N 19/157: Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/45: {performing compensation of the inverse transform mismatch, e.g. Inverse Discrete Cosine Transform [IDCT] mismatch}
- H04N 19/52: by predictive encoding
- H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
- H04N 19/186: the unit being a colour or a chrominance component
- H04N 19/587: involving temporal sub-sampling or interpolation, e.g. decimation or subsequent interpolation of pictures in a video sequence
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

An encoder which transforms a current block to be encoded in an image to encode the current block includes circuitry and memory. The circuitry, using the memory: determines a plurality of first transform basis candidates and transforms the current block using a transform basis included in the plurality of first transform basis candidates determined, when the current block has a first size; and determines one or more second transform basis candidates different from the plurality of first transform basis candidates and transforms the current block using a transform basis included in the one or more second transform basis candidates determined, when the current block has a second size larger than the first size.

## Claims

### Claim 1

An encoder comprising:
circuitry; and
memory,
wherein the circuitry, using the memory:
determines a first group of candidates and transforms a current block using a transform basis which is one of the candidates included in the first group of candidates determined, when the current block has a size of 16 or less; and
determines one second candidate outside of the first group of candidates and transforms the current block using a transform basis which is the second candidate determined, when the current block has a size larger than 16.

### Claim 2

An encoding method comprising:
determining a first group of candidates and transforming a current block using a transform basis which is one of the candidates included in the first group of candidates determined, when the current block has a size of 16 or less; and
determining one second candidate outside of the first group of candidates and transforming the current block using a transform basis which is the second candidate determined, when the current block has a size larger than 16.