“…A recent approach 0162-8828/97/$10.00 © 1997 IEEE [11] organizes the model base hierarchically, using parametric structural descriptions built from the CAD models of objects, where it is assumed that a complete 3D description of an object is available for its recognition. Other approaches to organizing object views for indexing include [12], [13], [14], [15], [16], but space limitations preclude a detailed discussion. In brief, our approach differs from them in terms of the features used (we use the shape spectrum for the first time), the usage of scale information (we normalize instead), construction of view aspects of volumetric parts of the object (we use shape summaries of whole object views), modelbase dependent feature prediction hierarchies and decision trees (in our case view grouping and modelbase organization are carried out independently), and object domain limitations (we report experiments on real free-form objects).…”