title: Python PIL jpeg quality
body: <p>I use python to save jpegs in a smaller quality</p>
  
  <pre><code>im = Image.open(file)
  im.save(cached_file, quality=80, optimize=True, progressive=True)
  </code></pre>
  
  <p>In some images however, the file size of the new image is larger than the original's. How can this happen?</p>