Most shape from shading (SFS) algorithms assumes that objects in the scene are Lambertian reflectors. That is, they do not absorb any radiation for any wavelength. However, real objects reflect only part of the incoming radiation, so that these algorithms usually perform poorly on images with non-uniform reflectivity. In this paper, an adaptation for such algorithms is proposed. The strategy mainly consists in guiding the SFS algorithm through the image so as not to violate the typical albedo uniformity assumption. In order to achieve this behavior, pixels in the image are iteratively grouped into regions coming from the same scene material until there are no more adjacent pixels satisfying this condition. The decision about the aggregation of a new pixel to a region is based on estimating its albedo and comparing it with the albedo of the region. During this process, SFS is applied only to the considered region and its results used in the albedo estimation procedure. Some experimental results with synthetic and real images are discussed at the end of the paper.