关键词: 小波阈值降噪, 阈值函数, 构造方法

Abstract: In order to solve the universality of threshold function in de-noising based on wavelet, a general constructing method applied to designing algorithm of wavelet threshold filtering is presented. Firstly, the aim curve of threshold function is confirmed. Secondly, a function family with different thresholds is constructed through the operation of the typical function curves satisfying the structural conditions, such as translation, rotation, scaling, and so on, and the function family approximates the objective function with different rate. Finally, the different threshold function is selected to reduce the noise according to the characteristics of the signal. Simulation and experimental results show that the characteristic of noise reduction is superior to soft and hard threshold function in SNR and MSE by this method, especially that has achieved a good balance in the sensitivity and smoothness.

Key words: de-noising based on wavelet, threshold function, constructing method