On combining multiple needle maps for recovering depth of 3-D object surface

The photometric stereo system can easily determine the surface orientation and relative depth of objects, but can not determine absolute depth. In order to determine absolute depth, this paper proposes an algorithm, this algorithm can obtain a needle map respectively by each camera of binocular photometric stereo system first, then solve disparities between the corresponding areas in two needle maps, finally combine disparities correctly, match them accurately and reconstruct 3-D depth of the object surface. This method is highly important for developing further exploring research on 3-D surface depth reconstruction and recovery of scene structure.