Anisotropic diffusion smoothing of mixed noise

Based on the fact that there is intrinsic drawback for median filter, linear filter and tradition anisotropic diffusion to mixed noise, a new diffusion model was proposed by modifying the calculation method of diffusion term and improving filter capability of the model. The improved model possesses band-pass filer characteristic, diffuses processing stability and satisfies the max-min principle. The simulation results show that the median filter is only proper for outlies noise and removes the thin line and corners of image. The linear filter extends or blurs the boundary of image. The anisotropic diffusion removes random noise effectively, but it brings about illusive edge and back diffusion for outlies noise. The improved model that possesses both median filter characteristics and anisotropic diffusion capability is proper for various mixed noise and can sufficiently protect the detailed characteristic such as corner, thin line and edge.