Pentland, A. P. (1986). Shading into texture. Artificial Intelligence, 29(2), 147-170.
Current shape-from-shading and shape-from-texture methods are applicable only to smooth surfaces, while real surfaces are often rough and crumpled. To extend such methods to real surfaces we must have a model that also applies to rough surfaces. The fractal surface model provides a formalism that is competent to describe such natural 3-D surfaces and, in addition, is able to predict human perceptual judgments of smoothness versus roughness. We have used this model of natural surface shapes to derive a technique for 3-D shape estimation that treats shaded and textured surfaces in a unified manner.