说明：  巴特沃斯低通滤波器、FIR低通滤波器、移动平均滤波器、中值滤波器、维纳滤波器、自适应滤波器和小波滤波器的比较
(Butterworth low-pass filter, FIR low-pass filter, moving average filter, median filter, Wiener filter, adaptive filter and wavelet filter comparison)