AN EDGE LABELING SCHEME FOR POLYHEDRA IN INCOMPLETE RANGE IMAGES

The use of range data has become quite popular in computer vision. One of the common methods for range data acquisition is based on coded light. However, the coded light approach suffers from the existence of shadow areas, where no range data can be measured. The borders of these shadow areas may correspond to real, geometric edges or to non-geometric edges. In this paper, we present a new approach to the interpretation of edges in range images of polyhedra. First, we integrate the edges extracted from the grey level and range image of a scene. Then, the edges are classified into one of the types jump, convex, concave, or non–geometric. While jump, convex and concave edges correspond to real edges, the non–geometric edges, which are caused by shadow, can be removed. Such a classification of physical edges together with the elimination of shadow edges potentially improves any subsequent object recognition step.