Image coding method and device on basis of wide-angle intra prediction and transform

    公开(公告)号:US11641471B2

    公开(公告)日:2023-05-02

    申请号:US17610985

    申请日:2020-05-27

    Abstract: An image decoding method according to the present document comprises the steps of: obtaining intra prediction mode information and an LFNST index; deriving an intra prediction mode of a current block on the basis of intra prediction mode information; when wide-angle intra prediction is applied to the current block, deriving a modified intra prediction mode by means of intra prediction mode remapping; deciding an LFNST set comprising LFNST matrices on the basis of the modified intra prediction mode; selecting one of the LFNST matrices on the basis of the LFNST set and LFNST index; and deriving transform coefficients for the current block on the basis of the selected LFNST matrix.

    Video coding method on basis of secondary transform, and device for same

    公开(公告)号:US11582486B2

    公开(公告)日:2023-02-14

    申请号:US17592768

    申请日:2022-02-04

    Abstract: A video decoding method according to the present document is characterized by comprising: a step for deriving transform coefficients through inverse quantization on the basis of quantized transform coefficients for a target block; a step for deriving modified transform coefficients on the basis of an inverse reduced secondary transform (RST) of the transform coefficients; and a step for generating a reconstructed picture on the basis of residual samples for the target block on the basis of an inverse primary transform of the modified transform coefficients, wherein the inverse RST using a transform kernel matrix is performed on transform coefficients of the upper-left 4×4 region of an 8×8 region of the target block, and the modified transform coefficients of the upper-left 4×4 region, upper-right 4×4 region, and lower-left 4×4 region of the 8×8 region are derived through the inverse RST.

    Transform-based image coding method, and apparatus therefor

    公开(公告)号:US11516484B2

    公开(公告)日:2022-11-29

    申请号:US17707000

    申请日:2022-03-29

    Abstract: An image decoding method according to the present document comprises: a residual coding step for parsing residual information received in a residual coding level and arranging transform coefficients for a current block according to a predetermined scanning order; a step for deriving residual samples by applying at least one of LFNST or MTS to the transform coefficients; and a step for generating a reconstructed picture on the basis of the residual samples, wherein the LFNST is performed on the basis of an LFNST index indicating an LFNST kernel, the MTS is performed on the basis of an MTS index indicating an MTS kernel, the LFNST index and the MTS index are signaled in a coding unit level, and the MTS index is signaled immediately after the signaling of the LFNST index.

    Method and device for signaling information related to slice in image/video encoding/decoding system

    公开(公告)号:US11509905B2

    公开(公告)日:2022-11-22

    申请号:US17826087

    申请日:2022-05-26

    Abstract: A method by which a video decoding device decodes a video, according to the present document, can comprise the steps of: parsing, from a bitstream, number information related to the number of slices of which the height within a tile of a current picture is explicitly signaled; parsing, from the bitstream, on the basis of the number information, height information related to the height of the slices of which the height is explicitly signaled; deriving the number of slices in the tile on the basis of the number information and the height information; generating prediction samples by predicting the current block of the current picture on the basis of the slices within the tile; generating reconstructed samples on the basis of the prediction samples; and generating a reconstructed picture for the current picture on the basis of the reconstructed samples.

    Signaling of information indicating transform kernel set in image coding

    公开(公告)号:US11503298B2

    公开(公告)日:2022-11-15

    申请号:US17555881

    申请日:2021-12-20

    Abstract: An image decoding method according to the present document comprises a step of generating residual samples of a current block on the basis of residual information, wherein the residual information comprises a multiple transform selection (MTS) index and information regarding transform coefficients, the residual samples are generated from transform coefficients according to the information regarding the transform coefficients by using a transform kernel set, the transform kernel set is determined by the MTS index from among transform kernel set candidates, at least one of bins of a bin string of the MTS index is derived on the basis of context coding, the context coding is performed based on a value of a context index with respect to the MTS index.

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