IMAGE DECODING DEVICE, IMAGE ENCODING DEVICE, IMAGE PROCESSING SYSTEM, AND PROGRAM

    公开(公告)号:EP3855736A1

    公开(公告)日:2021-07-28

    申请号:EP19862930.5

    申请日:2019-08-29

    申请人: KDDI Corporation

    摘要: An image decoding device includes a prediction unit configured to generate a prediction signal included in a prediction block based on a motion vector. The prediction unit is configured to perform refinement processing of setting a search range based on a reference position specified by the motion vector, specifying a corrected reference position having the smallest predetermined cost from the search range, and correcting the motion vector based on the corrected reference position. When a block size of the prediction block is larger than a predetermined block size, the prediction unit is configured to divide the prediction block into sub-block groups and perform the refinement processing for each sub-block.

    IMAGE DECODING DEVICE, IMAGE ENCODING DEVICE, IMAGE PROCESSING SYSTEM, IMAGE DECODING METHOD, AND PROGRAM

    公开(公告)号:EP3806459A1

    公开(公告)日:2021-04-14

    申请号:EP19815804.0

    申请日:2019-03-22

    申请人: KDDI Corporation

    摘要: An image decoding device includes: a decoding-side first generation unit that generates, for a target unit, a prediction sample of a first component; a decoding-side linear prediction unit that uses the sample of the first component and a prediction coefficient to generate a linear prediction sample of a second component; and a decoding-side second generation unit that uses the linear prediction sample of the second component to generate, for the target unit, a prediction sample of the second component. The decoding-side linear prediction unit uses a first coefficient as the prediction coefficient when the sample of the first component is equal to or below a threshold value, and uses a second coefficient which is different from the first coefficient as the prediction coefficient when the sample of the first component is greater than the threshold value. The threshold value is set on the basis of a parameter representing a distribution of or a change in a reference sample of the first component and/or the second component contained in a reference unit which is referenced for the target unit.

    MOVING IMAGE DECODING DEVICE, MOVING IMAGE DECODING METHOD, AND PROGRAM

    公开(公告)号:EP3905682A1

    公开(公告)日:2021-11-03

    申请号:EP19906288.6

    申请日:2019-12-06

    申请人: KDDI Corporation

    IPC分类号: H04N19/186 H04N19/593

    摘要: A moving picture decoding device 30 includes: a transform unit 34a sets a decoded luminance component of a prediction target block to the same number of samples as that of the chrominance component corresponding to the decoded luminance component of the prediction target block, and generates a luminance reference signal; a specification unit 34b specifies pixels of luminance having the minimum and maximum pixel values of the decoded luminance component adjacent to the decoded luminance component of the prediction target block, respectively, outputs luminance pixel values obtained from the specified pixels of luminance, and outputs chrominance pixel values obtained from pixels of pigment corresponding to the pixels of luminance; a derivation unit 34c derives a linear prediction parameter from the luminance pixel value, the chrominance pixel value, and a linear prediction model; a chrominance linear prediction unit 34d obtains a chrominance prediction signal by applying the linear prediction model based on the linear prediction parameter to the luminance reference signal; and an addition unit 34e adds the chrominance prediction signal and the chrominance residual signal to generate a reconstructed chrominance signal.