title: How to use tf.nn.max_pool_with_argmax correctly
body: <p>currently I play a little bit around with tensorflow to create a better understanding of machine learning an tensorflow itself. Therefore I want to visualize the methods (as much as possible) of tensorflow. To visualize max_pool I loaded an image and perform the method. After that I displayed both: input and output image.</p>
  
  <pre class="lang-py prettyprint-override"><code>import tensorflow as tf
  import cv2
  import numpy as np
  
  import matplotlib.pyplot as plt
  
  image = cv2.imread('lena.png')
  image_tensor = tf.expand_dims(tf.Variable(image, dtype=tf.float32), 0)
  
  #output, argmax = tf.nn.max_pool_with_argmax(image_tensor, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='SAME', name='pool1')
  output = tf.nn.max_pool(image_tensor, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='SAME', name='pool1')
  
  init = tf.initialize_all_variables()
  session = tf.Session()
  session.run(init)
  
  output = session.run(output)
  
  session.close()
  
  image = cv2.cvtColor(image, cv2.COLOR_RGB2BGR)
  plt.figure()
  plt.imshow(image)
  plt.show()
  
  output = cv2.cvtColor(output[0], cv2.COLOR_RGB2BGR)
  plt.figure()
  plt.imshow(255-output)
  plt.show() 
  </code></pre>
  
  <p>Everything works fine and I get this output (as expected)</p>
  
  <p><a href="https://i.stack.imgur.com/FFoKmm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/FFoKmm.png" alt="image (input)"></a>
  <a href="https://i.stack.imgur.com/YZhogm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YZhogm.png" alt="enter image description here"></a></p>
  
  <p>Now I wanted to test the method <code>tf.nn.max_pool_with_argmax</code> to get the argmax of the pooling operations. But if I uncomment the line </p>
  
  <p><code>output, argmax = tf.nn.max_pool_with_argmax(image_tensor, ksize=[1, 2, 2, 1], strides=[1, 2, 2, 1], padding='SAME', name='pool1')
  </code></p>
  
  <p>Python crashes with </p>
  
  <blockquote>
    <p>tensorflow.python.framework.errors.InvalidArgumentError: No OpKernel was registered to support Op 'MaxPoolWithArgmax' with these attrs
         [[Node: pool1 = MaxPoolWithArgmaxT=DT_FLOAT, Targmax=DT_INT64, ksize=[1, 2, 2, 1], padding="SAME", strides=[1, 2, 2, 1]]]</p>
  </blockquote>
  
  <p>I don't have an idea which argument is wrong because every argument should be correct (<a href="https://www.tensorflow.org/versions/r0.10/api_docs/python/nn.html#max_pool_with_argmax" rel="nofollow noreferrer">tensorflow docs</a>) ...</p>
  
  <p>Does anyone know what went wrong?</p>