“…In Euclidean space, medial axis transformations [34], [66], [20] and generalized Euclidean distance transformations [19], [41], [46] are widely studied for digital images and volume data. For spaces with non-Euclidean metrics, the domain of Voronoi diagrams has also been extended to spheres [4], [50], polyhedral surfaces [49], [30], [67], parametric surfaces [33], hyperbolic spaces [53] and the general Riemannian manifolds [65], [36], [52]. For detailed surveys, the reader is referred to [5], [51] and the references therein.…”