| CPC H04N 19/105 (2014.11) [H04N 19/137 (2014.11); H04N 19/159 (2014.11); H04N 19/176 (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 for a current block based on the prediction related information;
deriving reference picture lists for the current block;
deriving picture order count (POC) differences between each of reference pictures included in the reference picture lists and current picture;
deriving motion information including reference picture indices for symmetric motion vector differences (SMVD) based on the POC differences; and
generating predicted samples based on the motion information,
wherein the reference picture indices for the SMVD are derived based on short-term reference pictures included in the reference picture lists,
wherein the POC differences include a first POC difference for reference picture list 0 (L0) and a second POC difference for reference picture list 1 (L1),
wherein the first POC difference for the L0 is a POC difference between a first short-term reference picture included in the L0 and the current picture, and the second POC difference for the L1 is a POC difference between a second short-term reference picture included in the L1 and the current picture, and
wherein a reference picture index of the L0 for the SMVD is derived based on the first POC difference, and a reference picture index of the L1 for the SMVD is derived based on the second POC difference.
|