Motion vector estimation method and apparatus for use in an image signal

Abstract

An inventive apparatus estimates correct motion vectors between a current and its previous frames for feature points selected from the previous frame. A motion vector detector first determines a set of initial motion vectors for the feature points. Subsequently, a displacement generator provides N number of displacements to an initial motion vector of a selected feature point to thereby produce a set of N candidate motion vectors for the selected feature point, wherein the selected feature point is surrounded by its, e.g., six neighboring feature points to form a previous hexagon having a set of six triangles. And then, a predictor provides quasi-feature points in the current frame from the neighboring feature points through the use of the initial motion vectors thereof; and also generates a set of N selected quasi-feature points from the selected feature point by using the N candidate motion vectors. And a weight factor generator selectively generates one from a multiplicity of weigh factors based on position data of each of the pixels in the current hexagon and each of the N subject quasi-feature points. Finally, a motion vector selector selects a motion vector from the N candidate motion vectors corresponding to a set of six triangles in the current hexagon which yields a minimum error value among N error values obtained through the use of the weight factors between the current and the previous hexagons.