Abstract: Most of the wavelet threshold denoising method needs to calculate the corresponding threshold.The estimation of noise variance will directly affect the effect of threshold denoising method.This paper presented a new phase matching of the noise variance estimation method,using the method in real-time estimate the current noise.A new method of noise threshold was set up.The experiments show that the method can greatly improve the signal to noise ratio and can be made a very good denoising effect.

Key words: Phascmatching, Wavelet transform, Noise estimation, Wavclet threshold