CPC H04N 19/105 (2014.11) [H04N 19/132 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (2014.11); H04N 19/52 (2014.11)] | 20 Claims |
1. An image decoding method performed by a decoding apparatus, the method comprising:
obtaining image information comprising inter prediction mode information and residual information through a bitstream;
generating residual samples based on the residual information;
generating a sub-block merge candidate list for a current block based on the inter prediction mode information;
selecting one candidate from among candidates included in the sub-block merge candidate list;
generating L0 prediction samples and L1 prediction samples of the current block based on the selected candidate, wherein the weight index is for the weighted averaging;
generating prediction samples by weighted averaging the L0 prediction samples and the L1 prediction samples based on a weight index for the selected candidate, wherein the weight index is for the weighted averaging; and
generating reconstructed samples based on the prediction samples and the residual samples,
wherein the sub-block merge candidate list comprises a constructed affine merge candidate,
wherein the constructed affine merge candidate comprises at least one of a control point motion vector CPMV0 for a control point CP0, a control point motion vector CPMV1 for a control point CP1, a control point motion vector CPMV2 for a control point CP2 or a control point motion vector CPMV3 for a control point CP3,
wherein the CP0 is related to a top-left corner of the current block, the CP1 is related to a top-right corner of the current block, the CP2 is related to a bottom-left corner of the current block and the CP3 is related to a bottom-right corner of the current block,
wherein based on a case that the constructed affine merge candidate is generated based on {CP0, CP1}, the constructed affine merge candidate comprises CPMV0 and the weight index for the constructed affine merge candidate is equal to the weight index for the CP0, and
wherein based on a case that the constructed affine merge candidate is generated based on {CP1, CP2, CP3}, the constructed affine merge candidate comprises CPMV1 and the weight index for the constructed affine merge candidate is equal to the weight index for the CP1.
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