On 3D reconstruction from two perspective views
Hans-Hellmut Nagel, Bernd Neumann · International Joint Conference on Artificial Intelligence · 1981
A concise derivation is given for a compact nonlinear equation which specifies possible 3D rotations of rigid objects, compatible with measurements of five object points in two views. The insight provided by direct geometrical interpretation of this equation = which contains ULLMAN's polar equation as a special case - may be exploited for attempts to categorize the set of possible solutions.