title: python imageio image size without loading image to memory
body: <p>I am using imageio with Python. It seems to have a cleaner API than PIL and consorts, so I would like to continue using imageio instead of other tools.</p>
  
  <p>I know how to get image size:</p>
  
  <pre><code>height, width, channels = imageio.imread(filepath).shape
  </code></pre>
  
  <p>Is there a way to get the size of an image, without needing to load it fully to memory? This should be possible, isnt't it? At least for a number of formats that (I guess) have the image size in the header?</p>