Patent ID: 7412003

Claim:
A method for motion vector refinement, comprising: (a) providing a target DCT block, a corresponding motion vector estimate, and a reference frame of DCT blocks; (b) when a boundary of a first reference DCT block located by said motion vector estimate in said reference frame does not align with a boundary of any of said DCT blocks in said reference frame, (i) define a motion vector search window by adjoining DCT coefficients along the boundaries of said first reference DCT block in said reference frame; (ii) refine said motion vector estimate by searching over potential motion vectors which locate potential reference DCT blocks within said search window; and (c) when a boundary of a first reference DCT block located by said motion vector estimate in said reference frame aligns with a boundary of any of said DCT blocks of said reference frame, (i) define a motion vector search window by repeating DCT coefficients of the aligned boundary(es) of said first reference block in said reference frame; (ii) refine said motion vector estimate by searching over potential motion vectors which locate potential reference DCT blocks within said search window.