Patent ID: 11910002
Assignee: LG ELECTRONICS INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An image decoding method performed by a decoding apparatus, the method comprising:
obtaining residual information from a bitstream;
deriving reference subblocks inside a collocated reference picture for subblocks in a current block;
deriving a subblock-based temporal motion information candidate based on the reference subblocks;
deriving motion information for the subblocks in the current block based on the subblock-based temporal motion information candidate;
generating prediction samples of the current block based on the motion information for the subblocks in the current block;
generating residual samples of the current block based on the residual information; and
generating reconstruction samples based on the prediction samples and the residual samples,
wherein the reference subblocks are derived from the collocated reference picture by applying a motion shift to a below-right center sample position of each of the subblocks in the current block,
wherein the motion shift is performed based on a motion vector derived from a spatial neighbor block of the current block,
wherein the spatial neighbor block is left neighbor block,
wherein the subblock-based temporal motion information candidate includes subblock unit motion vectors, and
wherein a base motion vector is used as a subblock unit motion vector for a reference subblock that is not available among the reference subblocks.