title: Repeatedly convolving two large arrays [python]
body: <p>I'm working in Python.</p>
  
  <p>In a Monte Carlo scheme, I want to repeatedly convolve an image (of let's say 500x500 pixels) with a varying kernel, of between 50x50 and 200x200 pixels.</p>
  
  <p>I'm using <code>convolve_fft</code> from <code>astropy.convolution</code> to compute the convolution.</p>
  
  <p>Right now, the whole scheme is prohibitively slow. Odds are the answer to this question is simply 'no, there is not', but is there something I can do to speed things along?</p>