Falcidieno, BiancaSpagnuolo, Michela2015-10-052015-10-0519901017-4656https://doi.org/10.2312/egtp.19901023This paper presents a method for extracting and representang features of a topographic surface approximated by triangular tales An algorithm as given which computes characteristic regions (a. e. regions having concave, convex or planar shape), characteristic lanes (ridges, ravines, generic creases) and characteristic points (maxima, minima, saddle points) The result as a new surface description an terms of an attributed hypergraph representation called Characteristic Region Configuration Graph, an which characteristic regions are considered the basic describers of the surface shape and correspond to the nodes of the graph, whale the arcs and hyperarcs represent the relationships between regions derived from characteristic lanes and points10.2312/egtp.19901023