Estimating the albedo map of a face from a single image

This paper describes how a facial albedo map can be recovered from a single image using a statistical model that captures variations in surface normal direction. We fit the model to intensity data using constraints on the surface normal direction provided by Lambert´s law and then use the differences between observed and reconstructed image brightness to estimate the albedo map. We show that this process is stable under varying illumination and use the process to render images under novel illumination.