Using diffusion equations for improving performance of wavelet-based image denoising techniques

A new method based on anisotropic diffusion and wavelet transform is presented for image noise reduction. In the existing wavelet thresholding methods, the final noise reduced image has limited improvement. It is due to keeping the approximate coefficients of the image unchanged. These coefficients have the main information of the image. Since noise affects both the approximate and detail coefficients, in this research, the anisotropic diffusion technique for noise reduction is applied on the approximation band to alleviate the deficiency of the existing wavelet thresholding methods. The proposed method was applied on several standard noisy images and the results indicate superiority of the proposed method over the existing wavelet-based image denoising, anisotropic diffusion, fourth-order anisotropic diffusion and median filtering techniques.