TRANSFORM-BASED IMAGE CODING METHOD AND DEVICE

    公开(公告)号:US20220124351A1

    公开(公告)日:2022-04-21

    申请号:US17562923

    申请日:2021-12-27

    Abstract: An image decoding method according to the present disclosure includes deriving transform coefficients through dequantization based on the quantized transform coefficients for the target block; deriving modified transform coefficients based on an inverse reduced secondary transform (RST) for the transform coefficients; deriving residual samples for the target block based on an inverse primary transform for the modified transform coefficients; and generating a reconstructed samples based on the residual samples, and prediction samples derived based on an intra prediction mode for the target block, wherein the inverse RST is performed based on a transform kernel matrix selected from a transform set including a plurality of transform kernel matrices, the transform set is determined based on a mapping relationship according to the intra prediction mode applied to the target block, and a plurality of intra prediction modes including the intra prediction mode of the target block are mapped to one transform set.

    TRANSFORM-BASED IMAGE CODING METHOD AND DEVICE THEREFOR

    公开(公告)号:US20220086448A1

    公开(公告)日:2022-03-17

    申请号:US17535090

    申请日:2021-11-24

    Abstract: An image decoding method, according to the present document, may comprise the steps of: deriving transform coefficients for a current block on the basis of residual information; determining whether a significant coefficient is present in a second region excluding a first region in the top-left end of the current block; parsing a LFNST index from a bitstream if the significant coefficient is not present in the second region; deriving modified transform coefficients by applying a LFNST matrix, derived on the basis of the LFNST index, to transform coefficients of the first region; and deriving residual samples of the current block on the basis of an inverse primary transform of the modified transform coefficients.

    TRANSFORM IN INTRA PREDICTION-BASED IMAGE CODING

    公开(公告)号:US20220038744A1

    公开(公告)日:2022-02-03

    申请号:US17503788

    申请日:2021-10-18

    Abstract: An image decoding method according to the present document comprises the steps of: acquiring prediction-related information and residual-related information for a current block; deriving transform coefficients for the current block on the basis of the residual-related information; and generating residual samples of the current block on the basis of the transform coefficients, wherein the residual-related information includes low-frequency non-separable transform (LFNST) index information indicating information relating to non-separable transform for a low-frequency transform coefficient of the current block on the basis of a matrix-based intra prediction (MIP) flag.

    METHOD AND DEVICE FOR CODING TRANSFORM SKIP FLAG

    公开(公告)号:US20220021882A1

    公开(公告)日:2022-01-20

    申请号:US17294943

    申请日:2019-11-27

    Abstract: An image decoding method according to the present document may include: a step for determining whether a current block is a dual-tree type in which individual division structures are applied to a luma component block and a chroma component block of the current block; a step for determining whether the current block is the luma component block to which the dual-tree type is applied, when the current block is determined to be the dual-tree type; a step for parsing a transform skip flag indicating whether a transform skip is applied to the luma component block, when the current block is the luma component block; a step for deriving whether a transform skip is applied to the chroma component block according to a preset condition, when the current block is not the luma component block; and a step for deriving a residual sample on the basis of the transform skip flag and residual information on the current block.

    METHOD AND APPARATUS FOR PROCESSING IMAGAE SIGNAL

    公开(公告)号:US20210360248A1

    公开(公告)日:2021-11-18

    申请号:US17386261

    申请日:2021-07-27

    Abstract: Embodiments of the disclosure provide a method and apparatus for processing video signals. An image signal decoding method according to an embodiment of the disclosure comprises the steps of: determining, on the basis of the height and width of a current block, an input length and output length of a non-separable transform; determining a non-separable transform matrix corresponding to the input length and output length of the non-separable transform; and applying the non-separable transform matrix to the current block, wherein, when the height and width of the current block are 4 each, the input length and output length of the non-separable transform are determined to be 8 and 16 respectively.

    METHOD AND DEVICE FOR PERFORMING TRANSFORMATION BY USING LAYERED-GIVENS TRANSFORM

    公开(公告)号:US20210360247A1

    公开(公告)日:2021-11-18

    申请号:US17059027

    申请日:2019-05-31

    Abstract: The present invention provides a method for reconstructing a video signal by using a layered-givens transform, comprising the steps of: generating a transform block by performing entropy decoding and inverse quantization on a current block; performing an inverse secondary transformation on a left top specific area of the transform block by using the layered-givens transform; performing an inverse primary transformation on the block on which the inverse secondary transformation has been performed; and reconstructing the current block by using the block on which the inverse primary transformation has been performed, wherein the layered-givens transform includes a plurality of rotation layers and a permutation matrix.

    IMAGE CODING METHOD BASED ON SECONDARY TRANSFORM AND APPARATUS THEREFOR

    公开(公告)号:US20210329249A1

    公开(公告)日:2021-10-21

    申请号:US17349215

    申请日:2021-06-16

    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 a non-separable secondary transform; dequantizing the quantized transform coefficients to derive transform coefficients; deriving modified transform coefficients on the basis of a matrix operation of a transform kernel matrix in a transform set indicated by the transform index and a transform coefficient list corresponding to the magnitude of dequantized transform coefficients; clipping the modified transform coefficients to a predetermined range of values; and deriving residual samples for the target block on the basis of an inverse primary transform with respect to the modified transform coefficients clipped.

Patent Agency Ranking