Image denoising using modified Perona–Malik model based on directional Laplacian

The Perona-Malik (PM) model, or the anisotropic diffusion, shows good performance for image restoration. However, it suffers from the so-called staircasing effect if the contrast parameter is small and otherwise cannot preserve edges. This paper proposes a modified Perona-Malik (MPM) model based on directional Laplacian, which diffuses image along the edge direction of the original image. A slightly weighted Laplacian is also integrated to suppress noise. The proposed model can alleviate the staircasing effect, preserve sharp discontinuities, and remove noise simultaneously. Experimental results compared with several relevant methods demonstrate the good performance of the proposed algorithm.