1. A process for performing an estimate of global motion based on a sequence of subsequent video images or the like, such subsequent video images being represented by digital signals arranged in frames, and, for each estimate of a frame with respect to-another, comprising: choosing, from amongst a series of vectors originating from linear combinations of motion vectors resulting from estimates of previous frames and/or constant vectors, at least one winning vector, considered as the best match for estimating the motion occurring between two frames, including: performing a virtual overlay of the two frames to be compared mutually offset both horizontally and vertically by amounts identified by the motion vector subjected to testing; applying a matching mask of pixels to be subjected to testing; calculating, for all pixels selected, a cost function; and identifying the vector with the lowest cost function value as the best vector for the purposes of estimation.