RAM-based search engine for orthogonal-sum block match motion estimation system

摘要

A RAM-based search engine for updating a horizontal sum representing the sum of the values of N pixels contained in a horizontal row of a reference pixel array during a motion estimation search during which the reference pixel array is displaced by one pixel in a horizontal search direction during each of a plurality of iterations of the motion estimation search. The RAM-based search engine includes a horizontal sum modifier circuit that accumulates the values of the N pixels contained in the horizontal row of the reference pixel array prior to any displacement of the reference pixel array to produce the horizontal sum, and that updates the horizontal sum by computing the new horizontal sum using the following equation:where OSNEW is the new horizontal sum after the last displacement of the reference pixel array by one pixel in the horizontal direction, OSOLD is the horizontal sum prior to the last displacement of the reference pixel array by one pixel in the horizontal direction, a00 is the pixel value of the pixel that was the horizontal origin of the reference pixel array prior to the last displacement of the reference pixel array by one pixel in the horizontal direction, and ano is the pixel value of the pixel that is the horizontal origin of the reference pixel array after the reference pixel array has been displaced by one pixel to the right with respect to the previous position of the reference pixel array as a result of the last displacement of the reference pixel array by one pixel in the horizontal direction.