Combined diffusion scheme and sharpening filter for digital image denoising

Abstract

Nowadays, digital images play an important role in real life applications as well as in the area of research and technology. Most of these images are degraded due to the inaccuracy or limitations of the capturing, transmission and storage devices. Removal of noise from images is still a challenging task for many researchers because there is always a trade off between noise removal and fine edge preservation. The noisy image is decomposed into different frequency bands using Stationary Wavelet Transform (SWT). The noise in the image is considered to be Gaussian. The detail coefficients undergo threes holding using mean filter and wavelet coefficient magnitude. Inverse Stationary Wavelet Transform (ISWT) is performed. The resultant image is passed through a sharpening filter to get the denoised image that highlights edges and fine details in an image.