Surface skeletonization of volume objects

Abstract

Tools for quantitative analysis of volume images are becoming more important, as volume images are becoming more common in a number of application fields, but especially in biomedical tomographic images at different scales. Here we present a method for reducing a volume (3D) object to a surface skeleton. The original object can be recovered from its skeleton. The method is based on the notion of "multiple voxels," derived from that of "multiple pixels" in the 2D case. It consists of two phases. During the first phase non-multiple voxels are iteratively removed. During the second phase, the remaining set of voxels is thinned to a set of one-voxel thick surfaces and curves. This skeletonization method requires only a small number of local (3 × 3 × 3 neighbourhood) operations per voxel, no extra memory and no look-up tables. It is suited both for sequential and parallel implementation. We exemplify the results of the method on a number of 128 × 128 × 128 images.