For the curvature function of Curvature-Driven Diffusions model (CDD), this paper studies the impact of the CDD on the inpainting, and a novel inpainting model based on partial differential equation (PDE) is proposed which contains five sub-models. For simplification, a discrete model based on this PDE is given. Experimental results show that we can obtain better inpainting effects compared with each other from those sub-models