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: 同屏显示原图f1(m,n)和FFT(f1)的幅度谱图；-Generating an image f1 (m, n), wherein the image size is 256 × 256, the highlight bar to the middle of 128 × 32, 0 = dark, bright point = 100. Its FFT: screen display picture f1 (m, n) and the FFT (f1) of the amplitude spectrum