Obtaining 3-D Geometric Descriptions Of Polyhedra From Sets Of Their Perspective Projections

The most natural two-dimensional rep resentations of our three-dimensional world are perspective projections. Man, and man's "seeing machines" both input visual information in this form. Man processes this information to obtain a model of his surround, ings. It is quite natural therefore, to desire such a visual processing capability for man's machines. A first step on the path to such a facility was taken by Rcbacts (Ref. 1) in his procedure for modeling the objects shown in a single photograph. There are two drawbacks to this approach; (1) it can not resolve such visual ambiguities as shown in Fig. 1, and, (2) it is necessary to be able to break up the picture into a set of predetermined models.