INTRA PREDICTION METHOD AND APPARATUS IN IMAGE CODING SYSTEM

    公开(公告)号:US20220038691A1

    公开(公告)日:2022-02-03

    申请号:US17279459

    申请日:2019-09-03

    Abstract: An image decoding method performed by a decoding apparatus according to the present disclosure comprises the steps of: obtaining a reference sample line index of a current block and most probable mode (MPM)-related information; constructing an alternative MPM list on the basis of the reference sample line index; deriving an intra prediction mode of the current block on the basis of the alternative MPM list and the MPM-related information; and generating a predicted block of the current block on the basis of the intra prediction mode, wherein the alternative MPM list is constructed on the basis of an intra prediction mode of an upper adjacent block of the current block and an intra prediction mode of a left adjacent block of the current block.

    IMAGE PREDICTION METHOD AND DEVICE FOR DERIVING CHROMA INTRA PREDICTION MODE

    公开(公告)号:US20220021902A1

    公开(公告)日:2022-01-20

    申请号:US17299630

    申请日:2019-11-27

    Abstract: An image decoding method according to the present document includes: a step for deriving a luma intra prediction mode; and a step for generating a chroma candidate mode list for a chroma block including a preset number of chroma intra candidates by using at least one among a DM, a planar mode, a DC mode, a vertical mode, a horizontal mode, and an up-right diagonal mode, which are derived from the luma intra prediction mode, wherein the DM is a prediction mode corresponding to a center (CR) position of the luma block, and the chroma intra candidates other than the DM can be derived through a duplicate check of the DM and a prediction mode corresponding to any one among the top left (TL), top right (TR), bottom left (BL), and bottom right (BR) of the luma block, the planar mode, the DC mode, the vertical mode, and the horizontal mode.

    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 VIDEO SIGNAL BY USING INTRA-PREDICTION

    公开(公告)号:US20210281833A1

    公开(公告)日:2021-09-09

    申请号:US17257169

    申请日:2019-07-02

    Abstract: Embodiments of the present disclosure provide a method and an apparatus for processing a video signal through intra prediction. A method for processing a video signal according to an embodiment of the present disclosure may include: checking that intra prediction is applied to a current block including a current sample to be predicted; determining a first reference sample value on a first reference location from at least one of samples positioned at an upper horizontal line and a left vertical line adjacent to the current block, based on an intra-prediction direction of the current block; determining a second reference sample value on a second reference location positioned in an opposite direction to the intra-prediction direction from a location of the current sample or the first reference location; determining a distance between the first reference location and the current sample as a first distance and determining a distance between the second reference location and the current sample as a second distance; and generating a prediction value of the current sample using the linear interpolation prediction based on a sample value of the first reference sample, the first distance, a sample value of the second reference sample, and the second distance.

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

    公开(公告)号:US20210092356A1

    公开(公告)日:2021-03-25

    申请号:US16952259

    申请日:2020-11-19

    Abstract: A video decoding method according to this document includes deriving a first candidate intra prediction mode based on a first neighboring block located on a left side of a current block, deriving a second candidate intra prediction mode based on a second neighboring block located on an upper side of the current block, constructing a most probable mode (MPM) list for the current block based on the first candidate intra prediction mode and the second candidate intra prediction mode, deriving an intra prediction mode for the current block based on the MPM list, generating predicted samples by performing prediction for the current block based on the intra prediction mode, and generating a reconstructed picture for the current block based on the predicted samples.

    IMAGE DECODING METHOD AND APPARATUS USING VIDEO INFORMATION INCLUDING INTRA PREDICTION INFORMATION IN IMAGE CODING SYSTEM

    公开(公告)号:US20200021806A1

    公开(公告)日:2020-01-16

    申请号:US16507558

    申请日:2019-07-10

    Abstract: Provided is a video decoding method performed by a decoding apparatus, which includes: obtaining intra prediction information of the current block through a bitstream; deriving MPM (Most Probable Mode) list including MPM candidates of the current block; when a value of a MPM flag is 0, deriving an intra prediction mode of the current block based on the remaining intra prediction mode information, in which the intra prediction mode is one of remaining intra prediction modes excluding the MPM candidates; deriving a prediction sample of the current block based on the intra prediction mode; and deriving a reconstructed picture based on the prediction sample, in which the intra prediction information includes the MPM flag, the intra prediction information includes the remaining intra prediction mode information when the value of the MPM flag is 0, the MPM flag is coded through a fixed length (FL) binarization process, a binarization parameter for the FL binarization process is 1, the remaining intra prediction mode information is coded through a truncated binary (TB) binarization process, and a binarization parameter for the TB binarization process is 60.

    INTRA PREDICTION METHOD AND APPARATUS BASED ON MULTI-REFERENCE LINE IN IMAGE CODING SYSTEM

    公开(公告)号:US20250039366A1

    公开(公告)日:2025-01-30

    申请号:US18918823

    申请日:2024-10-17

    Abstract: An image decoding method performed by a decoding device according to the present document comprises the steps of: obtaining reference line index information and prediction information for a current block; determining an intra prediction mode of the current block on the basis of the prediction information; deriving a reference sample of the current block on the basis of the intra prediction mode and the reference line index information; and generating a prediction sample of the current block on the basis of the reference sample, wherein the intra prediction mode includes a non-directional intra prediction mode, and the reference sample is derived from among surrounding samples of the current block on the basis of the non-directional intra prediction mode and the reference line index information.

    CCLM-BASED INTRA-PREDICTION METHOD AND APPARATUS THEREFOR

    公开(公告)号:US20250030840A1

    公开(公告)日:2025-01-23

    申请号:US18905045

    申请日:2024-10-02

    Abstract: A picture decoding method, performed by a decoding apparatus according to the present dislosure, comprises the steps of: when an intra-prediction mode of a chroma block is a cross-component linear model (CCLM) mode, deriving neighboring chroma reference samples with respect to the chroma block; deriving neighboring luma reference samples of a luma block corresponding to the chroma block and luma samples in the luma block; deriving down-sampled neighboring luma reference samples and downsampled luma samples by down sampling the neighboring luma reference samples and the luma samples, respectively; deriving a linear model parameter on the basis of the down-sampled neighboring luma reference samples and the neighboring chroma reference samples; generating prediction samples with respect to the chroma block on the basis of the linear model parameter and the down-sampled luma samples of the luma block; and reconstructing the chroma block on the basis of the prediction samples with respect to the chroma block.

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