产生一图像 f1(m,n)，其中图像大小为256×256，中间亮条为128×32，暗处=0，亮处=100。对其进行FFT：1.若令f2(m,n)=(-1)^(m+n)*f1(m,n)，重复以上过程，比较二者幅度谱的异同；2若将f2(m,n)顺时针旋转90 度得到f3(m,n)，试显示FFT(f3)的幅度谱，并与FFT(f2)的幅度谱进行比较；-Generating an image f1 (m, n), wherein the image size is 256 256, the highlight of the intermediate 12832, 0 = dark, bright Department 100. Its FFT:. 1 if so f2 (m, n) = (-1) ^ (m+n)* f1 (m, n), repeat the above process, comparing the amplitude spectrum of both the similarities and differences　2 If f2 (m , n) 90 degrees clockwise to get f3 (m, n), try to display FFT (f3) the amplitude spectrum and with the FFT (f2) to compare the magnitude of the spectrum