Inpainting Algorithm for Dunhuang Mural Based on Improved Curvature-Driven Diffusion Model

The cracks of Dunhuang mural have the characteristic of complex shape and irregular scratches,and it is prone to false edges,staircase effects and long repair time by using curvature-driven diffusion(CDD)algorithm.An adaptive inpainting algorithm for Dunhuang mural based on improved CDD model is proposed in this paper.Firstly,the gradient disappearance problem in CDD algorithm is improved to make the diffusion term more reasonable.Then an adaptive control strategy is proposed.Different repair models can be selected to dynamically self-adaptively repair when the curvature of the damaged area of mural crack is different.Finally,a corner diffusion repair is carried out by using smooth function to achieve the purposes of denoising and edge protection.The experimental results of restoration of real Dunhuang mural show that the algorithm can solve the problems of unnatural transition edges and long repair time of CDD algorithm.The proposed method is superior to other algorithms in PSNR and restoration time evaluation.