Near point light source location estimation from shadow edge correspondence

The problem of near point light source location estimation is considered. The approach described here is based on a relationship between the cast shadow edge, the shadow-casting surface, and the light source. Given an optical-depth image pair available from an RGB-D camera, a method for near point light source location estimation is described. The method can be applied to a shadow-casting object with arbitrary and unknown geometry. Exhaustive multidimensional search is avoided by the proposed iterative one-dimensional search algorithm. Experimental results with real images are included.