High accurate subspace extension of phase correlation for global motion estimation

摘要

A method for achieving high sub-unit accuracy during global motion estimation of sequential video frame images is described herein. The method estimates the global motion using an existing phase-correlation approach, and further refines it to a sub-unit level using the neighborhood values of the phase correlation surface peak The method determines the sub-unit displacement direction by examining the signs of the peak of phase correlation surface and its two nearest neighbors. The method determines the sub-unit displacement magnitude by applying the ratio of associated phase correlation values to a 5^th-order polynomial function. The method then computes the actual motion by adding the sub-unit displacement value to the global motion value as calculated by the phase-correlation approach.