“…Skeletonizaton approaches can be broadly classified into four categories: 1) thinning/peeling algorithms [22,23,24,25,26], 2) discrete domain algorithms based on the Voronoi diagram [27,28,29], 3) algorithms based on distance transform [30,31,32,33,34], and 4) algorithms based on mathematical morphology [35,36,37,38].…”