NONLINEAR IMAGE FILTERING WITH EDGE AND CORNER ENHANCEMENT

We describe a method of nonlinear image filtering for noise reduction and edge enhancement using anisotropic diffusion. The method is designed to enhance not only edges but corners and T junctions as well. As in the recent work of Perona and Malik [1], the method roughly corresponds to a nonlinear diffusion process with backward heat flow across the strong edges. Such a process is ill posed, making the results depend strongly on how the algorithm differs from the diffusion process. We study two ways of modifying the equations using simulations on a variable grid.