Encoder, decoder, encoding method, and decoding method

    公开(公告)号:US12143583B2

    公开(公告)日:2024-11-12

    申请号:US17071470

    申请日:2020-10-15

    Abstract: An encoder includes circuitry and memory. Using the memory, the circuitry: performs a transform process of (i) applying a first transform to a prediction residual signal indicating a difference between a current block to be encoded and a prediction image of the current block and (ii) further applying a second transform to a transform result of the first transform; and in the second transform, selects one transform basis (i) from a first group of candidates when a size of the current block is a first block size and (ii) from a second group of candidates when the size of the current block is a second block size different from the first block size, the first group including one or more candidates for a transform basis, the second group being different from the first group.

    ENCODER, DECODER, ENCODING METHOD, AND DECODING METHOD

    公开(公告)号:US20240333934A1

    公开(公告)日:2024-10-03

    申请号:US18738296

    申请日:2024-06-10

    Abstract: An encoder includes memory and circuitry which: (i) encodes an image block; (ii) when encoding the image block: binarizes coefficient information indicating coefficients of the image block; and controls whether to apply arithmetic encoding to a binary data string obtained by binarizing the coefficient information; and (iii) when binarizing the coefficient information: binarizes the coefficient information according to a first syntax structure when arithmetic encoding is applied to the data string and a predetermined condition is not satisfied; binarizes the coefficient information according to a second syntax structure when arithmetic encoding is applied to the data string and the predetermined condition is satisfied; binarizes the coefficient information according to the second syntax structure when no arithmetic encoding is applied to the data string; and subtracts 1 from a value of an initial non-zero coefficient when no arithmetic encoding is applied to the data string when encoding the image block.

    Encoder, decoder, encoding method, and decoding method

    公开(公告)号:US12069266B2

    公开(公告)日:2024-08-20

    申请号:US17691623

    申请日:2022-03-10

    CPC classification number: H04N19/13 H04N19/105 H04N19/176 H04N19/46 H04N19/91

    Abstract: An encoder includes circuitry and memory coupled to the circuitry. In residual coding of a current block to which an orthogonal transform is not applied, when coefficient information flags relating to a coefficient in the current block are encoded, the circuitry: performs a level mapping process to transform the coefficient to a second coefficient by using a predicted value, in which the predicted value is determined based on neighboring coefficients of the coefficient within the current block; encodes second coefficient information flags by Context-based Adaptive Binary Arithmetic Coding (CABAC), each of the second coefficient information flags relating to the second coefficient; and encodes a remainder value of the coefficient with Golomb-Rice code, and when the coefficient information flags are not encoded, in operation, the circuitry: skips the level mapping process; and encodes a value of the coefficient with the Golomb-Rice code.

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