US 11,722,659 B2
Affine motion prediction-based image decoding method and apparatus using affine MVP candidate list in image coding system
Jaeho Lee, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Filed by LG ELECTRONICS INC., Seoul (KR)
Filed on Mar. 1, 2022, as Appl. No. 17/684,036.
Application 17/684,036 is a continuation of application No. 17/068,534, filed on Oct. 12, 2020, granted, now 11,303,887.
Application 17/068,534 is a continuation of application No. 16/870,352, filed on May 8, 2020, granted, now 10,841,576.
Application 16/870,352 is a continuation of application No. PCT/KR2019/011733, filed on Sep. 10, 2019.
Claims priority of provisional application 62/729,407, filed on Sep. 10, 2018.
Prior Publication US 2022/0182613 A1, Jun. 9, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/513 (2014.01); H04N 19/105 (2014.01); H04N 19/129 (2014.01); H04N 19/132 (2014.01); H04N 19/137 (2014.01); H04N 19/176 (2014.01)
CPC H04N 19/105 (2014.11) [H04N 19/129 (2014.11); H04N 19/132 (2014.11); H04N 19/137 (2014.11); H04N 19/176 (2014.11)] 17 Claims
OG exemplary drawing
 
1. A video decoding method performed by a decoding apparatus, comprising:
obtaining motion prediction information for a current block from a bitstream;
constructing an affine Motion Vector Predictor (MVP) candidate list for the current block;
deriving Control Point Motion Vector Predictors (CPMVPs) for Control Points (CPs) of the current block based on the affine MVP candidate list;
deriving Control Point Motion Vector Differences (CPMVDs) for the CPs of the current block based on the motion prediction information;
deriving Control Point Motion Vectors (CPMVs) for the CPs of the current block based on the CPMVPs and the CPMVDs; and
generating a reconstructed picture for the current block by performing inter prediction on the current block based on the CPMVs,
wherein the constructing the affine MVP candidate list comprises:
checking whether an inherited affine MVP candidate is available, wherein the inherited affine MVP candidate is derived when the inherited affine MVP candidate is available;
checking whether a constructed affine MVP candidate is available, wherein the constructed affine MVP candidate is derived when the constructed affine MVP candidate is available, and the constructed affine MVP candidate includes a candidate motion vector for CP0 of the current block, a candidate motion vector for CP1 of the current block, and a candidate motion vector for CP2 of the current block;
when the number of derived affine MVP candidates including the inherited affine MVP candidate and the constructed affine MVP candidate is less than 2, deriving a first affine MVP candidate, wherein the first affine MVP candidate is an affine MVP candidate including a specific motion vector as candidate motion vectors for the CPs and the specific motion vector is an available motion vector among the candidate motion vector for the CP0, the candidate motion vector for the CP1, and the candidate motion vector for the CP2.