title: Bilinear upsample in tensorflow?
body: <p>I want to do a simple bilinear resize (not necessarily by an integer factor) in TensorFlow. For example, starting from a (32,3,64,64) tensor, I would like a (32,3,96,96) tensor, where each 64x64 has been rescaled by a factor of 1.5 using bilinear interpolation. What is the best way to do that?</p>
  
  <p>I would like this to support arbitrary factors > 1, not just 1.5 specifically.</p>
  
  <p>Note: the operation on each 64x64 would be the same as what <code>skimage.transform.rescale (scale=1.5, order=1)</code> does.</p>