title: Plot the 2D FFT of an image
body: <p>I'm trying to plot the 2D FFT of an image:</p>
  
  <pre><code>from scipy import fftpack, ndimage
  import matplotlib.pyplot as plt
  
  image = ndimage.imread('image2.jpg', flatten=True)     # flatten=True gives a greyscale image
  fft2 = fftpack.fft2(image)
  
  plt.imshow(fft2)
  plt.show()
  </code></pre>
  
  <p>But I get <code>TypeError: Image data can not convert to float</code>.</p>
  
  <p><strong>How to plot the 2D FFT of an image?</strong></p>