Object matching on irregular pyramid

The matching of an object, a region of an image segmentation, to a template is a heavy computation process and is not very robust. We represent an object by a region adjacency graph (RAG) on the top of which a pyramid (a decreasing sequence of RAG) is built according to a set of rules, which verify some uniqueness and uniformity properties. The contraction process preserves the structure of the RAG across the pyramid´s levels, and the rules are chosen according to the characteristics of the template. By building such a pyramid and then by a top-down process to match all the sub-graphs we have a linear parallel complexity time, with a robust match and a partial match relative to the given set of rules