A new image denoising method based on the bilateral filter

In this paper we propose a new method to reduce noise in digital images. The method is based on the bilateral filter. The bilateral filter is a nonlinear filter that does spatial averaging without smoothing edges. The spatial averaging aspect of the bilateral filter is very crucial; the bilateral filter has been shown to work better than wavelet thresholding in some recent papers. The proposed method improves the bilateral filter through decomposing a signal into its frequency components. In this way, noise in different frequency components can be eliminated. Experimental results with both simulated and real images are given. In addition to this new method, we also provide an empirical study of the optimal parameter selection for the bilateral filter.