Image Restoration Based on Fourth-Order PDE Model

In order to avoid the blocky effects of second-order PDE model and preserve edges, a new fourth-order PDE model was proposed in this paper. Based on four-neighbor system, a simple and symmetrical difference scheme was also developed to make the model more efficient and reliable. Median filtering was utilized to alleviate the speckle effects in the processed image at last. We remove the Gaussian noises from different images and compare the PSNR values and visual qualities of the results with traditional methods. Numerical experimental results show that the proposed models give the best performance in restoring images, especially in edge preservation and enhancement.