Image-denoising method based on wavelet transform and mean filtering

Combined with wavelet transform and mean filtering, an efficient image-denoising method was presented. Firstly, noised image was decomposed to various frequency sub-band images by wavelet transform. According to the respective characteristics, high frequency sub-band images at horizontal, vertical and angular directions were denoised by three different filter templates, without any changes to the low frequency approximation image. Denoised-image was obtained by composing the three high frequency detail images with mean filtering and low frequency approximation image. Experiment result shows that the noise of the image is removed effectively. At the same time, the detail of the image is kept well. The method has better denoising effect than single wavelet thresholding method and mean filtering method.