Overview on Wavelet Image Denoising
小波图象去噪综述

Wavelet image denoising has been well acknowledged as an important method of image denoising. Based on many literatures of wavelet denoising, this paper attempts to make an overview of wavelet image denoising. First, it describes wavelet denoising in two ways, one from its mathematics background, the other from filter theory of signal processing. Then this paper classifies wavelet image denoising methods into three classes that includes shrinkage based method, projection based method, and correlation based method, and describes them respectively. Considering the important role that coefficient model plays in a wavelet based denoising scheme, this paper also discusses three kinds of wavelet coefficient model, including intra level model, inter level model, and hybrid model that combine the first two together. Usage of simultaneous wavelet transformations, the relationship between wavelet image denoising and wavelet image compression and wavelet denoising under different noise models are also covered here in order to give an overview as complete as possible. At the end, the future trend of wavelet image denoising is pointed out, though, in personal opinion.