3D shape modelling using a multi-scale surface model

This paper presents a method for extracting the 3D shape of objects from 3D gray level images. The object surface is assumed to be described by a bicubic B-spline surface. The detection of the object shape is achieved using a hierarchical approach in which the object surface is successively estimated using the spline model at increased scales. At each scale, the model is iteratively fitted to a set of measurement points which are believed to be on the object surface. The measurement points are detected by searching for voxels with the strongest edge response along the direction normal to the model surface. Searching for the measurement points is controlled within a search radius determined based on the edge strength at the points on the current model surface. The result is a parametric surface approximating the object surface to be detected