Topological active nets for object-based image retrieval

Extraction of relevant image objects and their matching for retrieval applications is proposed in this paper. Objects are represented by using a two dimensional deformable structure, referred to as active net, capable to adapt to relevant image regions according to chromatic and edge information. In particular, an extension of the active nets has been defined which permits the nets to break themselves, thus increasing their capability to adapt to objects with complex topological structure (e.g., objects with holes). The resulting representation allows a joint description of color, shape and structural information of extracted objects. A similarity measure between active nets is also defined and validated in a set of retrieval experiments on the ETH-80 objects database.