Patent Document ID: 5557341
Application ID: 08133089
Patent Status: 1

Claim One:
1. An iterative block-matching method for determining a final motion vector for blocks of a predetermined minimum size, the block being within a selected image I.sub.s, the selected image I.sub.s being one in a sequence of digital images, the method using successively reduced block size of the same resolution as blocks of previous sizes, the method comprising the steps of: a) selecting one of the images in the sequence as the selected image I.sub.s ; b) dividing the selected image I.sub.s into blocks of a predetermined maximum size; c) selecting at least one reference image I.sub.r from among the remaining images in the sequence for comparison against the selected image I.sub.s ; d) selecting one of the blocks of pixels, within the selected image I.sub.s, upon which to operate; e) determining a motion vector between the selected block within the selected image I.sub.s and a corresponding area within the reference image I.sub.r ; wherein the step e) includes the steps f)-i) as follows: f) predicting a motion vector for the selected block as a function of at least one predetermined motion vector value, the predicted motion vector representing predicted movement of the selected block between a position P.sub.0 in the selected image I.sub.s and a position P.sub.p in the reference image I.sub.r ; g) establishing, according to a predetermined search pattern, a plurality of meta blocks in the reference image I.sub.r such that each meta block is located near the position P.sub.p, the search pattern being a configuration of search points, each meta block having a center located on a search point; h) determining a degree of similarity between each meta block and the selected block by calculating a matching criterion; and i) selecting the meta block with the matching criterion that most probably corresponds to actual motion of the selected block between the selected image I.sub.s and the reference image I.sub.r, thereby selecting a temporary motion vector pointing between the position P0 in the selected block and the search point about which is centered the selected meta block; j) repeatedly performing, until there is selected a temporary motion vector for each of the blocks of the selected image I.sub.s, the substeps of: j1) selecting another block of pixels as the selected block from among the remaining block or blocks, within the selected image I.sub.s, upon which to operate; and j2) performing the step e) for the newly selected block; k) repeatedly performing, until there is selected a temporary motion vector for each of the blocks of the predetermined minimum size within the selected image I.sub.s, the substeps of: k1) reducing, if the size of the selected block is greater than the predetermined minimum size, the size of the selected block by dividing the selected image I.sub.s into smaller blocks, while preserving the resolution thereof; and k2) performing the steps d)-k); and l) establishing, after the step j), the temporary motion vector as the final motion vector for each of the predetermined minimum size blocks in the selected image I.sub.s, thereby forming a final motion vector field therefor.