145 The Study of Removing Image Noise with Median Filter and Wavelet Transform

Median filtering is a cornerstone of modern image processing and is used extensively in smoothing and denoising applications. In this paper, three different median filtering algorithms, four different wavelet filtering algorithms and the method of Median Filter and Wavelet combination are compared based on their ability to reconstruct noise-affected images. It turns out that median filter method is particularly effective when the noise consists of strong spike-like components (known as salt and pepper noise). Wavelet transforms have been utilized effectively for image denoising, providing a means to exploit the relationships between coefficients at multiple scales. But the median filter and wavelet filter are not particularly effective to eliminate the Gaussian noise. We will propose a new method of Median Filter and Wavelet combination, the experiment results show that this proposed algorithm can both preserve image detail information well and remove the noises, particularly Gaussian noises.