Pruning Medial Axes

Abstract

The medial axis is an attractive shape feature; however, its high sensitivity to boundary noise hinders its use in many applications. In order to overcome the sensitivity problem some regularization has to be performed. Pruning is a family of medial axis regularization processes, incorporated in most skeletonization and thinning algorithms. Pruning algorithms usually appear in a variety of application-dependent formulations. Inconsistent terminology used until now prevented analysis and comparison of the various pruning methods. Indeed many seemingly different algorithms are in fact equivalent. In this paper we suggest the rate pruning paradigm as a standard for pruning methods. The proposed paradigm is a framework in which it is easy to analyze, compare, and tailor new pruning methods. We analyze existing pruning methods, propose two new methods, and compare the methods via a model-based analysis. The theoretical analysis is supported by simulation results of the various pruning methods.