A technique for identifying the material properties of objects in an image using multiple images taken through a polarizing lens at various rotations in front of a stationary camera (only the filter moves). Using these images, it is possible to obtain the classification of material surfaces at all points on a spectacular highlight. The algorithm is demonstrated on laboratory images. The authors assume a point source, the theory can only be applied at points where specular reflection dominates. Extensions of the theory to deal with extended light sources, which greatly increase the portion of the image giving rise to specular reflection, are also considered. >