Calculation of surface position and orientation using the photometric stereo method

The three-dimensional position and the surface orientation of a solid object are determined from video images using one camera position and three different light sources. This method, called the photometric stereo method, solves the shape-from-shading problem by numerically solving a set of nonlinear equations. Experimental measurements show accurate results for uniform near-Lambertian surfaces, especially for smooth surface areas. This method, which uses point light sources, is the first demonstration of measuring depth (distance) from shaded video images