	US 12,262,048 B2
	Inter prediction-based image coding method and apparatus
Naeri Park, Seoul (KR); Junghak Nam, Seoul (KR); and Hyeongmoon Jang, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Filed by LG ELECTRONICS INC., Seoul (KR)
Filed on Dec. 20, 2023, as Appl. No. 18/391,106.
Application 18/391,106 is a continuation of application No. 18/114,003, filed on Feb. 24, 2023, granted, now 11,895,325.
Application 18/114,003 is a continuation of application No. 17/559,964, filed on Dec. 22, 2021, granted, now 11,627,334.
Application 17/559,964 is a continuation of application No. PCT/KR2020/008133, filed on Jun. 24, 2020.
Claims priority of provisional application 62/865,958, filed on Jun. 24, 2019.
Prior Publication US 2024/0129520 A1, Apr. 18, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H04N 19/52 (2014.01); H04N 19/105 (2014.01); H04N 19/107 (2014.01); H04N 19/132 (2014.01); H04N 19/139 (2014.01); H04N 19/172 (2014.01); H04N 19/176 (2014.01); H04N 19/573 (2014.01); H04N 19/70 (2014.01)

CPC H04N 19/52 (2014.11) [H04N 19/105 (2014.11); H04N 19/107 (2014.11); H04N 19/132 (2014.11); H04N 19/139 (2014.11); H04N 19/172 (2014.11); H04N 19/176 (2014.11); H04N 19/573 (2014.11); H04N 19/70 (2014.11)]

4 Claims

1. An image decoding method performed by a decoding apparatus, the method comprising:

obtaining image information including prediction related information from a bitstream;

deriving an inter prediction mode based on the prediction related information;

constructing motion vector predictor candidate lists for a current block based on the inter prediction mode;

deriving motion vectors for the current block based on the motion vector predictor candidate lists;

deriving reference picture lists for the current block, wherein the reference picture lists include an L0 reference picture list and an L1 reference picture list;

determining whether an L0 reference picture in the L0 reference picture list is a short-term reference picture;

deriving a first picture order count (POC) difference between the L0 reference picture in the L0 reference picture list and a current picture;

deriving an L0 symmetric motion vector difference reference index;

determining whether an L1 reference picture in the L1 reference picture list is a short-term reference picture;

deriving a second POC difference between the L1 reference picture in the L1 reference picture list and the current picture;

deriving an L1 symmetric motion vector difference reference index; and

generating predicted samples based on the motion vectors, the L0 symmetric motion vector difference reference index and the L1 symmetric motion vector difference reference index,

wherein the motion vectors are derived based on motion vector predictors derived based on the motion vector predictor candidate lists and motion vector differences,

wherein bi-prediction is applied to the current block,

wherein the motion vector differences include an L0 motion vector difference for an L0 prediction and an L1 motion vector difference for an L1 prediction,

wherein the L1 motion vector difference is derived based on the L0 motion vector difference,

wherein the L0 symmetric motion vector difference reference index is derived based on the first POC difference and a determination that the L0 reference picture in the L0 reference picture list is the short-term reference picture, and

wherein the L1 symmetric motion vector difference reference index is derived based on the second POC difference and a determination that the L1 reference picture in the L1 reference picture list is the short-term reference picture.