Matching Deformable Regions Using Local Histograms of Differential Invariants

This paper presents a technique to enable deformable regions to be matched using image databases based on the information provided by the differential invariants of local histograms for the key-region. We shall show how this technique is robust enough to deal with local deformations, viewpoint changes, lighting changes, large motions of the tracked object and small changes in image rotation and scale. The proposed algorithm is based on the building of a specific template where an orthogonal representation space is associated with each of its locations. This space is calculated from neighboring information provided by a vector of local invariants calculated on each of the image’s pixels. Unlike other well-known color-based techniques, this algorithm only uses the pixels’ gray level values.