A novel method is presented for grouping range image regions such that each group of regions represents a meaningful part of an object. The set of regions, defined as a convex region set (CRS), is obtained by analyzing the boundary types between a pair of regions. The boundary types are classified as convex, concave and jump boundaries. If two regions share a convex boundary it is assumed that they are inseparable regions, thus describing the same part (object). The CRSs are determined by a region boundary graph (RBG) which is defined as a graph whose nodes represent regions, and the edges represent boundaries: convex and concave. Since jump boundaries represent no physical contact in 3-D, they are represented as null edges. A CRS is defined as a set of regions (or nodes in an RBG) such that for each pair of regions in the set, there is a path, which is represented only by convex edges. The physical interpretation is that a CRS represents part of an object such that the regions in the set cannot be separated. >
['Joon H. Han', 'Richard A. Volz']
Region grouping from a range image