A Comparison of Some Gradient Threshold Estimators for the Nonlinear Diffusion of Perona-Malik. A Novel Proposal to Improve Edges Detection in Mammography Images. - Reinaldo Barrera Travieso; Angela Mireya León-Mecías; José A. Mesejo-Chiong; Richard M. Méndez-Castillo (IWAIPR, 2023)