Detecting specular reflections using Lambertian constraints

A scheme is described for detecting specularities based on a characterization of Lambertian surfaces. Real surfaces are not simple composites of Lambertian and specular surfaces but evidence suggests that away from specularities they do not deviate from the Lambertian model by more than a factor of three or so. This proves adequate to serve as a constraint for specularity detection. Two independent tests identify image regions where the constraint is violated. The detector is shown to perform well on a variety of real images.