Dual-primal skeleton: A thinning scheme for vertex sets lying on a surface mesh

Abstract

We present a new algorithm for the skeletonization of shapes lying on surface meshes, which is based on a thinning scheme with a granularity that is twice as fine as that of other thinning methods, since the proposed approach uses dual-primal iterations in the region of interest to perform the skeleton extraction. This dual operator is built on specific construction rules, and it is applied until idempotency, which provides a better geometric positioning of the skeleton compared to other thinning methods. Moreover, the skeleton has the property of ensuring the same topological guarantees as other homotopic thinning approaches: the skeleton is thin, connected and can include Y-branches and cycles if the input region contains holes.