Fourth order nonlinear diffusion filters for multiplicative noise removal

Abstract

The second order partial differential equations based multiplicative noise removal filters produce step edges (staircase artifacts) in the filtered image. This paper proposes two fourth order nonlinear diffusion filters, an isotropic filter and an anisotropic filter, which do not allow these artifacts. Through numerical simulations it is shown that the proposed isotropic filter produces the filtered image in a relatively shorter time, with noticeable improvement in the quality, when compared to a second order filter and the proposed anisotropic diffusion filter.