“…As inspiration for a general rule for breaking scenes into elemental parts, we look to psychophysical studies, mostly performed on 2D images, which suggest that the transition between convex and concave image parts might be indicative of the separation between objects and/or their parts [13,25,21,15,7,4]. While this feature has been used in machine vision to some degree [10,17,20,24,11] success has remained limited and more recent studies were forced to combine this feature with additional, often very complex feature constellations to achieve good scene partitioning [20,24,11]. It, thus, appears that direct transfer from 2D to 3D of the conventional, geometrically-defined convex-concave transition criterion shown in Fig.…”