Abstract: Based on the multilevel threshold de-noising method foundation, mean value approximation (MVA) was used to pretreat the noising image. The pretreatment of the noising image was first carried out so as to reducethe variance of the white noise and then the multilevel threshold value denoising method was used to reduce noising. This method is more advantageous to separate signal and noise. The result indicates that this method is an effective and feasible one to the image denoising so as to enhance the signaltonoise ratio.

Key words: multiwavelet transform, multilevel threshold, mean value approximation