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US 11,457,209 B2Granted
Image decoding method for deriving weight index information for biprediction, and device for same
AssigneeLG Electronics Inc.
InventorsNaeri Park, Junghak Nam, Hyeongmoon Jang
Life of this patent
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Abstract
According to the disclosure of the present document, when the inter-prediction type of the current block indicates biprediction, weight index information for a candidate in a merge candidate list or sub-block merge candidate list can be derived, and coding efficiency can be raised.
Claims14
An image decoding method performed by a decoding apparatus, the image decoding method comprising:
- receiving image information including inter-prediction mode information through a bitstream;
- generating a merge candidate list of a current block based on the inter-prediction mode information;
- selecting one candidate from among candidates included in the merge candidate list;
- deriving motion information on the current block based on the selected candidate;
- generating L0 prediction samples and L1 prediction samples of the current block based on the motion information;
- and
- generating prediction samples of the current block based on the L0 prediction samples, the L1 prediction samples, and weight information, wherein the weight information is weight information for a bi-prediction and is derived based on a weight index for the selected candidate,
- wherein the candidates include a constructed affine merge candidate, and the constructed affine merge candidate includes control point motion vectors (CPMVs),
- wherein based on a case that the constructed affine merge candidate is generated based on {CP0, CP1, CP3}, a weight index for the constructed affine merge candidate is set equal to a weight index for the CP0, 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 and the CP3 is related to a bottom-right corner of the current block.
6 more elements
An image encoding method performed by an encoding apparatus, the image encoding method comprising:
- determining an inter-prediction mode of a current block and generating inter-prediction mode information indicating the inter-prediction mode;
- generating a merge candidate list of the current block based on the inter-prediction mode information;
- generating selection information indicating one of candidates included in the merge candidate list;
- and
- encoding image information including the inter-prediction mode information and the selection information,
- wherein motion information of the candidate indicated by the selection information is for deriving L0 prediction samples and L1 prediction samples of the current block,
- wherein weight information is for generating prediction samples of the current block based on the L0 prediction samples and the L1 prediction samples, wherein the weight information is for a bi-prediction and is derived based on a weight index for the candidate indicated by the selection information,
- wherein the candidates include a constructed affine merge candidate, and the constructed affine merge candidate includes control point motion vectors (CPMV),
- wherein, based on a case that the constructed affine merge candidate is generated based on {CP0, CP1, CP3}, a weight index for the constructed affine merge candidate is set equal to a weight index for the CP0, and
- 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 and the CP3 is related to a bottom-right corner of the current block.
7 more elements
A non-transitory computer readable digital storage medium storing a bitstream generated by an image encoding method, the method comprising:
- determining an inter-prediction mode of a current block and generating inter-prediction mode information indicating the inter-prediction mode;
- generating a merge candidate list of the current block based on the inter-prediction mode information;
- generating selection information indicating one of candidates included in the merge candidate list;
- and
- encoding image information to generate the bitstream, wherein the image information includes the inter-prediction mode information and the selection information,
- wherein motion information of the candidate indicated by the selection information is for deriving L0 prediction samples and L1 prediction samples of the current block,
- wherein weight information is for generating prediction samples of the current block based on the L0 prediction samples and the L1 prediction samples, wherein the weight information is for a bi-prediction and is derived based on a weight index for the candidate indicated by the selection information,
- wherein the candidates include a constructed affine merge candidate, and the constructed affine merge candidate includes control point motion vectors (CPMV),
- wherein, based on a case that the constructed affine merge candidate is generated based on {CP0, CP1, CP3}, a weight index for the constructed affine merge candidate is set equal to a weight index for the CP0, and
- 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 and the CP3 is related to a bottom-right corner of the current block.
7 more elements
Dependencies are inferred from the claim text.