title: Merging non-overlapping array blocks
body: <p>I divided a (512x512) 2-dimensional array to 2x2 blocks using this function. </p>
  
  <pre><code>skimage.util.view_as_blocks (arr_in, block_shape)
  array([[ 0,  1,  2,  3],
     [ 4,  5,  6,  7],
     [ 8,  9, 10, 11],
     [12, 13, 14, 15]])
     &gt;&gt;&gt; B = view_as_blocks(A, block_shape=(2, 2))
     &gt;&gt;&gt; B[0, 0]
     array([[0, 1],
            [4, 5]])
     &gt;&gt;&gt; B[0, 1]
     array([[2, 3],
            [6, 7]])
  </code></pre>
  
  <p>Now I need to put the same blocks to their original places after manipulation but I couldn't see any function in skimage for that.</p>
  
  <p>What's the best way to merge the non-overlapping arrays as it was before?</p>
  
  <p>Thank you!</p>