Modified Numerical Scheme for Perona-Malik Model in Image Restoration

This paper proposes a difference scheme based on nonlinear diffusion Perona-Malik model for numerical calculation in image restoration. Our scheme can adapt to determine the tangent directions to the isophote lines based on two mutually orthogonal directional derivatives, which results that diffusion is along the edges as much as possible. One of typical edge stopping functions for Perona-Malik model is modified in order to improve robust calculation and satisfy the compatibility, stability and convergence for our numerical scheme. Computer experimental results indicate that the algorithm corresponding to our numerical scheme is very efficient for noise removal in regardless whether the noise is serious or not.