Method and Apparatus Using Affine Motion Estimation with Control-Point Motion Vector Refinement

An apparatus for video coding, the apparatus comprising one or more electronic circuits or processors arranged to:

• receive input data associated with a current block, wherein the input data comprise pixel data for the current block to be encoded at an encoder side or coded data associated with the current block to be decoded at a decoder side, and the current block is coded in an affine mode;
• determine two or more CPMVs (Control-Point Motion Vectors) or two or more corner-subblock motions for the current block;
• refine said two or more CPMVs or said two or more corner-subblock motions independently to generate two or more refined CPMVs;
• generate a merge list or an AMVP (Advanced Motion Vector Prediction) list comprising said one or more refined CPMVs;
• and
• encode or decode the current block using a motion candidate selected from the merge list or the AMVP list.

A method of video coding, the method comprising:

• receiving input data associated with a current block, wherein the input data comprise pixel data for the current block to be encoded at an encoder side or coded data associated with the current block to be decoded at a decoder side, and the current block is coded in an affine mode;
• applying an affine model determined for the current block to neighbouring reference subblocks of the current block to derive affine-transformed reference blocks of neighbouring reference subblocks;
• determining one or more templates based on the affine-transformed reference blocks;
• reordering a set of merge candidates, based on corresponding cost values measured using said one or more templates, to derive a set of reordered merge candidates;
• and
• encoding or decoding the current block using a motion candidate selected from a merge list comprising the set of reordered merge candidates.

An apparatus for video coding, the apparatus comprising one or more electronic circuits or processors arranged to:

• receive input data associated with a current block, wherein the input data comprise pixel data for the current block to be encoded at an encoder side or coded data associated with the current block to be decoded at a decoder side, and the current block is coded in an affine mode;
• apply an affine model determined for the current block to neighbouring reference subblocks of the current block to derive affine-transformed reference blocks of neighbouring reference subblocks;
• determine one or more templates based on the affine-transformed reference blocks;
• reorder a set of merge candidates, based on corresponding cost values measured using said one or more templates, to derive a set of reordered merge candidates;
• and
• encode or decode the current block using a motion candidate selected from a merge list comprising the set of reordered merge candidates.