3D recovery of polyhedra by rectangularity heuristics

The three-dimensional shape of a polyhedron is reconstructed from its perspectively projected image by finding rectangular corners. If a corner is known to be rectangular, its three-dimensional configuration is analytically computed, and hence the surface gradients of the faces incident to it are also determined. In order to decide which corners are rectangular, the rectangularity heuristics are introduced, i.e. corners are assumed to be rectangular as long as no inconsistency arises as a result. An optimization technique is presented in order to cope with the problem of insufficiency of information and inconsistency due to error and noise