Patent ID: 11949874
Assignee: LG ELECTRONICS INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A method of transmitting a bitstream generated by an image encoding method, the image encoding method comprising:
deriving a prediction sample of a current block based on motion information of the current block;
determining whether prediction refinement with optical flow (PROF) applies to the current block;
deriving, based on that the PROF applies to the current block, a difference motion vector for each sample position in the current block;
deriving a gradient for each sample position in the current block;
deriving a PROF offset based on the difference motion vector and the gradient; and
deriving a refined prediction sample for the current block based on the PROF offset,
wherein the deriving the gradient comprises right-shifting a neighboring prediction sample value at each sample position in the current block by a first shift, and
wherein a value of the first shift is fixed as 6.