To improve image de-nosing effect

in this paper

a new method based on discrete cosine transform (DCT) in Contourlet domain is proposed

which utilizes noise energy rather than relying on accurate estimation of noise variance to perform image de-noising.This new method not only overcomes the psuedo-Gibbs phenomenon of the hard-thresholding method but also can avoid signal distortion which is caused by the soft-thresholding.Experiments show that the performance of the proposed method is obviously superior to other methods both in vision and in PSNR and is of more practical use.