Image coding method based on secondary transform, and device therefor

    公开(公告)号:US11936911B2

    公开(公告)日:2024-03-19

    申请号:US17689277

    申请日:2022-03-08

    Abstract: An image decoding method comprises the steps of: deriving transform coefficients through inverse quantization on the basis of quantized transform coefficients for a target block; deriving modified transform coefficients on the basis of an inverse reduced secondary transform (RST) for the transform coefficients; and generating a restoration picture on the basis of residual samples for the target block, on the basis of an inverse primary transform for the modified transform coefficients, wherein the inverse RST is performed on the basis of: transform sets determined by a mapping relation according to an intra prediction mode applied to the target block; and a transform kernel matrix selected from among two transform kernel matrices included in each of the transform sets, and is performed on the basis of: whether the inverse RST is applied; and a transform index for indicating any one of the transform kernel matrices included in the transform sets.

    Method and apparatus for processing image signal

    公开(公告)号:US11882310B2

    公开(公告)日:2024-01-23

    申请号:US18113936

    申请日:2023-02-24

    CPC classification number: H04N19/593 H04N19/122 H04N19/176

    Abstract: Embodiments of the present disclosure provide a method and device for processing a video signal. A method for decoding an image signal according to an embodiment of the present disclosure comprises the steps of: determining a non-separable transform set index indicating a non-separable transform set used for a non-separable transform of a current block from among non-separable transform sets predefined on the basis of an intra-prediction mode of the current block; determining. as a non-separable transform matrix, a transform kernel indicated by a non-separable transform index for the current block from among transform kernels included in the non-separable transform set indicated by the non-separable transform set index; and applying the non-separable transform matrix to an upper left region which of the current block, which is determined according to the width and height of the current block, wherein each of the predefined non-separable transform sets includes two transform kernels.

    Method and apparatus for processing image signal

    公开(公告)号:US11863746B2

    公开(公告)日:2024-01-02

    申请号:US17386261

    申请日:2021-07-27

    CPC classification number: H04N19/122 H04N19/159 H04N19/176 H04N19/61

    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 processing video signal

    公开(公告)号:US11856196B2

    公开(公告)日:2023-12-26

    申请号:US17422629

    申请日:2020-01-09

    CPC classification number: H04N19/12 H04N19/176 H04N19/46 H04N19/61

    Abstract: Embodiments of the present invention provide a method and device for processing a video signal. A method for processing a video signal according to an embodiment of the present specification comprises the steps of: acquiring position information of a last significant coefficient according to scanning order in a transform block; and performing residual coding on the basis of the position information of the last significant coefficient. The position information of the last significant coefficient includes a first prefix for a column position of the last significant coefficient and a second prefix for a row position of the last significant coefficient; a range of the first prefix is determined on the basis of an effective width of the transform block; a range of the second prefix is determined on the basis of an effective height of the transform block; if a width of the transform block corresponds to a first size, the effective width of the transform block is determined to be a second size; if a height of the transform block corresponds to the first size, the effective height of the transform block is determined to be the second size; and the second size is configured to be smaller than the first size.

Patent Agency Ranking