BLOCK-BASED Optical Flow Estimation FOR MOTION COMPENSATED PREDICTION IN VIDEO CODING

A device comprising:

• a processor configured to:
• decode, from a compressed bitstream, a motion vector for a current block of a current frame;
• identify a location of a reference block within an un-generated reference frame;
• generate the reference block using a forward reference frame and a backward reference frame without generating the un-generated reference frame, wherein to generate the reference block comprises to:
• identify an extended reference block by extending the reference block at each boundary of the reference block by a number of pixels related to a filter length of a filter used in sub-pixel interpolation;
• and
• generate pixel values of only the extended reference block by performing a projection using the forward reference frame and the backward reference frame without generating the whole of the un-generated reference frame;
• and
• decode the current block based on the reference block and the motion vector.

A non-transitory computer-readable storage medium having stored thereon a compressed bitstream, wherein the compressed bitstream is configured for decoding by operations comprising:

• decoding, from the compressed bitstream, a motion vector for a current block of a current frame;
• identifying a location of a reference block within an un-generated reference frame;
• generating the reference block using a forward reference frame and a backward reference frame without generating the un-generated reference frame by:
• identifying an extended reference block by extending the reference block at each boundary of the reference block by a number of pixels related to a filter length of a filter used in sub-pixel interpolation;
• and
• generating pixel values of only the extended reference block by performing a projection using the forward reference frame and the backward reference frame without generating the whole of the un-generated reference frame;
• and
• decoding the current block based on the reference block and the motion vector.