Optimal warping prediction for video coding

Warping, also known as control grid interpolation, estimates intensities in the present frame through an interpolation of motion vectors-typically with bilinear interpolation. This paper presents a method for computing optimal interpolation parameters for warping prediction. Conventional bilinear warping, while mostly effective, has been known to exhibit unreliable performance in certain situations. Since both block-matching (BMA) and bilinear warping are candidate solutions for optimal warping, the performance of optimal warping is lower bounded by both bilinear warping and BMA, therefore vastly reducing the inconsistency problem. Furthermore, this optimality criterion is applicable to any category of motion vector, including that of block-matching. Thus we are able to demonstrate the optimal usage, under linear operations in the motion domain, of BMA motion vectors