The application of partial difference equation (PDE) in image analysis and processing is discussed The PDE models for image denoising, the principle of PDE denoising their reduction approach and development processes are introduced The relations of PDE, regularization and wavelet shrinkage are analyzed, the application of PDE in image restoration and image superresolution are introduced a preview of its development is given, and point out that the best way to evolve PDE is combining PDE with wavelet, regula...