Reconstructing shape from shading images under point light source illumination

A photometric method called point source illuminating stereo is proposed for determining the 3D shape of an object from multiple shading images under point light source illumination. When the surface is a perfect diffuser with uniform reflectance, an algorithm for the determination of 3D shape with positions is developed by using the method of least squares and relying on the principle of the monocular vision and the inverse square law for illuminance. In the proposed method, the number of the necessary images is four for the general surface, and can be reduced to three for the continuous surface