Hybrid variational restoration technique based on second- and fourth-order diffusions

A novel compound PDE-based image restoration approach is described in this paper. The proposed hybrid denoising technique is expressed as a variational scheme based on second and fourth order nonlinear diffusions. This PDE variational model is described first. Then, the differential model corresponding to the variational problem is determined, by applying the Euler-Lagrange equation. A mathematical investigation is performed on the resulted fourth-order PDE, then an explicit numerical approximation scheme based on the finite-difference method is constructed for this model. The performed denoising experiments and method comparison are also described.