Medial residues of piecewise linear manifolds

Skeleton structures of objects are used in a wide variety of applications such as shape analysis and path planning. One of the most widely used skeletons is the medial axis, which is a thin structure centered within and homotopy equivalent to the object. However, on piecewise linear surfaces, which are one of the most common outputs from surface reconstruction algorithms, natural generalizations of typical medial axis definitions may fail to have these desirable properties. In this paper, we propose a new extension of the medial axis, called the medial residue, and prove that it is a finite curve network homotopy equivalent to the original surface when the input is a piecewise linear surface with boundary. We also develop an efficient algorithm to compute the medial residue on a triangulated mesh, building on previously known work to compute geodesic distances.