A Progressive Technique for Identifying Known Shapes in Images

Information Retrieval in digital libraries is at the same time a hard task and a crucial issue. While the primary type of information available in digital documents is usually text, images play a very important role because they pictorially describe concepts that are dealt with in the document. Unfortunately, the semantic gap separating such a visual content from the underlying meaning is very wide, and additionally image processing techniques are usually very demanding in computational resources. Hence, only recently the area of Content-Based Image Retrieval has gained more attention. In this paper we describe a new technique to identify known objects in a picture. It is based on shape contours, and works by progressive approximations to save computational resources and to improve preliminary shape extraction. Small (controlled) and more extensive experiments are illustrated, yielding interesting results.