Hessian matrix-based fourth-order anisotropic diffusion filter for image denoising

Image denoising is one of important tasks in image processing. Diffusion filter-based methods have been widely used for image denosing. In order to solve the staircase effect introduced by second-order diffusion filter, different fourth-order diffusion filters were proposed, which can achieve good performance on image denoising. However, fourth-order diffusion filter often suffers over-smoothness. In this paper, we propose an anisotropic fourth-order diffusion filter for astronomical image denoising, in which the eigenvalue of Hessian matrix is introduced for preserving edge information. The experimental results of denoising on several astronomical images show that the proposed method can achieve better performance than several other methods.