Virginio Cantoni Luigi Cinque Stefano Levialdi Luca Lombardi Evaluating Digital Angles by a Parallel Diffusion Process. 133-138 1995 conf/iciap/1995 ICIAP db/conf/iciap/iciap1995.html#CantoniCLL95 http://dx.doi.org/10.1007/3-540-60298-4_248