灰度图像的二维傅里叶变换(cv_gray_fft2)，二维傅里叶变换结果的幅值计算(cv_abs)，频谱平移(cv_gray_fft2shift)，将数值归一化到0到255区间(cv_range_0to255)是非常常用的四个功能！所以写成四个函数，方便将来调用！附运行截图~并附对应的MATLAB程序！-Dimensional Fourier transform of the grayscale image (cv_gray fft2), two-dimensional Fourier transform results to calculate the amplitude (cv_abs), spectral translation (cv_gray_fft2shift), the value normalized to range　0 to 255 (cv_range_0to255) is very common four function! so written as four function to facilitate future calls! attached run shot- along with the corresponding MATLAB program!