Reversible Skeletonization by (5,7,11)-Erosion

Abstract

The skeleton is a useful tool for analyzing the shape of a non trivial planar figure, namely a connected set of pixels which has variable width and protrusions of different size. The skeleton is a connected subset of the figure, centrally placed in it and with the same connectivity order. Its pixels are labeled with their distance from the complement of the figure, and its branches are located in correspondence with the protrusions regarded as significant in the problem domain. To facilitate both figure interpretation and further processing, the skeleton is generally required to be a linear set, i.e., to be the union of simple digital arcs and curves where no pixel can be removed without creating disconnection or shortening.