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.

    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.

    Image coding method based on quadratic transform, and apparatus therefor

    公开(公告)号:US11483589B2

    公开(公告)日:2022-10-25

    申请号:US17394734

    申请日:2021-08-05

    Abstract: An image decoding method according to the present document comprises the steps of: receiving a quantized transform coefficient for a target block and a transform index for non-separable quadratic transform; deriving transform coefficients by inversely quantizing the quantized transform coefficient; deriving corrected transform coefficients on the basis of a transform kernel matrix in a predetermined transform set indicated by the transform index; and deriving residual samples for the target block on the basis of inverse linear transform for the corrected transform coefficients, wherein when the target block is divided into a predetermined number of sub-blocks and is coded by intra prediction, the corrected transform coefficients are derived in units of the sub-blocks, and the transform index is received for the target block.

    TRANSFORM-BASED IMAGE CODING METHOD AND DEVICE THEREFOR

    公开(公告)号:US20220248018A1

    公开(公告)日:2022-08-04

    申请号:US17719925

    申请日:2022-04-13

    Abstract: An image decoding method according to the present document comprises a step for performing inverse first-order transform and inverse non-separable transform on a residual sample. The inverse non-separable transform is performed on the basis of a transform index indicating a predetermined transform kernel matrix, the inverse first-order transform is performed on the basis of a multiple transform selection (MTS) index indicating MTS for a horizontal transform kernel and a vertical transform kernel, and a syntax element bin string for the transform index is derived on the basis of first context information when a tree type for a split structure of a target block is not a single tree type and is derived on the basis of second context information when the tree type is the single tree type.

    IMAGE DECODING METHOD FOR RESIDUAL DATA CODING IN IMAGE CODING SYSTEM, AND APPARATUS THEREFOR

    公开(公告)号:US20220174324A1

    公开(公告)日:2022-06-02

    申请号:US17673201

    申请日:2022-02-16

    Abstract: An image decoding method performed by a decoding apparatus, according to the present document, comprises the steps of: acquiring syntax elements for a first transform coefficient through an n-th transform coefficient of a current block, wherein the syntax elements are syntax elements according to a first residual data coding structure of TSRC; and acquiring syntax elements for an n+1st transform coefficient through a last transform coefficient of the current block, wherein the syntax elements are syntax elements according to a second residual data coding structure of the TSRC, wherein the number of context-coded syntax elements for the first transform coefficient through the n-th transform coefficient is equal to the maximum number of context-coded bins of the current block, and the syntax elements according to the second residual data coding structure include coefficient level information and a sign flag for a transform coefficient.

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