cse 252c Fall 2004 Project Report: A Model of Perpendicular Texture for Determining Surface Geometry

Three-dimensional objects distributed over a surface occlude each other in a manner dependent upon the angle (sigma) between the surface normal and the viewer. Leung and Malik note that occlusion allows the top of the objects to be seen, but not the bottom. For the case where the objects are differently colored as a function of height, the color content of the scene will thus depend upon sigma. A model is described that predicts the fraction of color expected to be present in each portion of the image, for a given value of sigma. This model can be compared to the actual color fractions in an image of unknown sigma, in order to furnish an error function, so that the sigma can be found using an optimization scheme. A set of synthetic images of cylinders on a plane are generated, and sigma is found to a mean accuracy of two degrees.