程序用来消除周期性噪声干扰信号。要求在图像频域中设计一Butterworth陷波器，其阶数n和陷波器半径D0由理论知识通过自己的探索得出，理解二者对滤波器性能的影响。-Procedures used to eliminate the periodic noise signal. Request images to design a Butterworth frequency domain notch filter, and its order n and the radius of notch