Ricardo Fabbri Luciano da Fontoura Costa Julio C. Torelli Odemir Martinez Bruno 2D Euclidean distance transform algorithms: A comparative survey. 2008 40 ACM Comput. Surv. 1 http://doi.acm.org/10.1145/1322432.1322434 db/journals/csur/csur40.html#FabbriCTB08