On finding the ends of straight homogeneous generalized cylinders

Algorithms to detect pairs of edges that could be ends of a straight homogeneous generalized cylinder (SHGC) are proposed. Geometrical constraints for the ends of an SHGC are utilized to group edge elements and edge segments in a complex image. Two methods are investigated. The first algorithm is for a subset of SHGCs for which scaling factors of the cross section at both ends are the same. The second algorithm is for any SHGC. However, a modified version is implemented to reduce computation; given a reference and edge, it finds the edges possibly paired with it. Several examples of ends extracted from real images are reported to show the feasibility of the algorithm.<<ETX>>