一种新的小波阈值函数，并与两种已存在的阈值函数进行去噪效果对比。该阈值函数在阈值处连续，且可避免产生恒定误差。-A new wavelet thresholding function, and with the two kinds of the existing threshold function de-noising effect of contrast. The threshold value of the threshold function is continuous, and can