Faithful Least-Squares Fitting of Spheres, Cylinders, Cones and Tori for Reliable Segmentation

This paper addresses a problem arising in the reverse engineering of solid models from depth-maps. We wish to identify and fit surfaces of known type wherever these are a good fit. This paper presents a set of methods for the least-squares fitting of spheres, cylinders, cones and tori to three-dimensional point data. Least-squares fitting of surfaces other planes, even of simple geometric type, has been little studied. Our method has the particular advantage of being robust in the sense that as the principal curvatures of the surfaces being fitted decrease (or become more equal), the results which are returned naturally become closer and closer to those surfaces of ‘simpler type’, i.e. planes, cylinders, cones, or spheres which best describe the data, unlike other methods which may diverge as various parameters or their combination become infinite.