Shape from textured and shaded surface

A novel 3-D shape model is developed to describe a 3-D surface image by considering the scene image as the superposition of a smooth shaded image and a random texture image. The modified reflectance map function is applied to describe the deterministic part, and the orthographically projected fractional differencing periodic (OPFDP) model is chosen to describe the random texture, because of its ability to represent the coarseness of the surface and the texture pattern, which is nonisotropically distributed due to the 3-D rotation, at the same time. For estimating the surface orientation parameters, a hybrid method which uses both the least-squares and the maximum-likelihood estimates is applied directly to the given intensity values of the image. These techniques are illustrated by synthetic examples.