1. Distance transformation and skeletons for shape feature analysis;Toriwaki,1992
2. Sequential operations in digital picture processing;Rosenfeld;J. Ass. Comput. Mach.,1966
3. Distances defined by neighborhood sequences;Yamashita;Pattern Recognition,1986
4. Distance transformations in arbitrary dimensions;Borgefors;CVGIP,1984
5. A new distance transformation approximating the Euclidean distance;Borgefors,1986