title: Correct dim parameter in tf.nn.l2_normalize(x, dim, epsilon=1e-12, name=None) for RGB picture
body: <p>I want to use tensorflows</p>
  
  <pre><code>tf.nn.l2_normalize(x, dim, epsilon=1e-12, name=None)
  </code></pre>
  
  <p>method to normalize each channel seperately in a (32x32x3) RGB image.</p>
  
  <p>How do I have to set the </p>
  
  <pre><code>dim
  </code></pre>
  
  <p>parameter to achieve that? </p>