Finally, it gave an image de-noising algorithm of coherence enhancing diffusion, which used wavelet coefficients to estimate the image edge according to the wavelets time-frequent analysis function.

Several experiments were finished and then find the explanation for the diffusion of the Ag clusters towards the oil edge.

Anisotropic diffusion has good effect on reducing noise and preserving edge, in fact its an iterative process. An important question is to decide when the process should be stopped.