title: Deconvolution2D layer in keras
body: <p>This layer in not ready documented very well and I'm having a bit of trouble figuring out exactly how to use it.<br>
  I'm Trying something like:  </p>
  
  <pre><code>input_img = Input(shape=(1, h, w))
  x = Convolution2D(16, 7, 7, activation='relu', border_mode='valid')(input_img)
  d = Deconvolution2D(1, 7, 7, (None, 1, 2*h, 2*w))
  x = d(x)
  </code></pre>
  
  <p>but when I try to write <code>d.output_shape</code>, I get the original shape of the image instead of twice that size (which is what I was expecting).<br>
  Any help will be greatly appreciated!</p>