TRANSFORM COEFFICIENT CODING METHOD AND DEVICE THEREFOR

    公开(公告)号:US20210274185A1

    公开(公告)日:2021-09-02

    申请号:US17217526

    申请日:2021-03-30

    Abstract: An image decoding method performed by a decoding device according to the present document comprises a step of receiving a bitstream containing residual information, and a step of deriving a quantized transform coefficient for a current block on the basis of the residual information contained in the bitstream, wherein the residual information includes a context syntax element coded on the basis of the context, and if the size of a transformation block is changed as much as a sub-block region having a predetermined size and the current block is the last sub-block in the sub-block region and the last quantized transform coefficient is in the current block, then the step of deriving a quantized transform coefficient includes context-based decoding of the context syntax element on the basis of a predetermined maximum value for the context syntax element, wherein the maximum value is determined on the basis of the size of the sub-block region.

    METHOD FOR DECODING IMAGE ON BASIS OF CCLM PREDICTION IN IMAGE CODING SYSTEM, AND DEVICE THEREFOR

    公开(公告)号:US20250159210A1

    公开(公告)日:2025-05-15

    申请号:US19022299

    申请日:2025-01-15

    Abstract: A video decoding method performed by a decoding apparatus according to the present disclosure includes deriving one of a plurality of cross-component linear model (CCLM) prediction mode as a CCLM prediction mode of the current chroma block, deriving a sample number of neighboring chroma samples of the current chroma block based on the CCLM prediction mode of the current chroma block, a size of the current chroma block, and a specific value; deriving the neighboring chroma samples of the sample number, calculating CCLM parameters based on the neighboring chroma samples and the down sampled neighboring luma samples, deriving prediction samples for the current chroma block based on the CCLM parameters and the down sampled luma samples and generating reconstructed samples for the current chroma block based on the prediction samples, wherein the specific value is derived as 2.

    INTRA PREDICTION-BASED IMAGE CODING METHOD AND DEVICE USING MPM LIST

    公开(公告)号:US20250113024A1

    公开(公告)日:2025-04-03

    申请号:US18980322

    申请日:2024-12-13

    Abstract: An image decoding method according to the present document derives a left mode, which is a candidate intra prediction mode for a left peripheral block of a current block, derives an upper mode, which is a candidate intra prediction mode for an upper peripheral block of the current block, constructs an MPM list on the basis of the left mode and the upper mode, derives an intra prediction mode of the current block on the basis of the MPM list, generates prediction samples of the current block on the basis of the intra prediction mode, generates a restoration picture of the current block on the basis of the prediction samples, and derives the left mode or the upper mode as one from among candidate intra prediction modes of the MPM list, on the basis of when the left mode and the upper mode are not the same and the left mode and the upper mode are respectively a planar mode and a DC mode.

Patent Agency Ranking