This chapter addresses the nonlinear partial differential equation (PDE)-based image denoising and restoration domain, detailing our most important contributions in this field. It describes PDE-based filtering models for various types of noise and images. Thus, the first three sections present 2D image restoration techniques related to different noise distributions. The first one introduces several effective nonlinear diffusion-based models, in variational and non-variational form, for additive white Gaussian noise (AWGN) reduction. The nonlinear PDE-based quantum noise filtering solutions are described in the second section, while the variational and anisotropic diffusion schemes dealing successfully with the noise mixtures are discussed in the third section.