title: Deep Dream Code does not generate recognizable patterns
body: <p>I've tried to create my own Deep Dream Algorithm with this Code:</p>
  
  <pre><code>import tensorflow as tf
  import matplotlib.pyplot as plt
  import numpy as np
  import inception
  
  img = np.random.rand(1,500,500,3)
  net = inception.get_inception_model()
  tf.import_graph_def(net['graph_def'], name='inception')
  graph = tf.get_default_graph()
  sess = tf.Session()
  layer = graph.get_tensor_by_name('inception/mixed5b_pool_reduce_pre_relu:0')
  gradient = tf.gradients(tf.reduce_mean(layer), graph.get_tensor_by_name('inception/input:0'))
  softmax = sess.graph.get_tensor_by_name('inception/softmax2:0')
  iters = 100
  init = tf.global_variables_initializer()
  
  sess.run(init)
  for i in range(iters):
      prediction = sess.run(softmax, \
                            {'inception/input:0': img})
      grad = sess.run(gradient[0], \
                            {'inception/input:0': img})
      grad = (grad-np.mean(grad))/np.std(grad)
      img = grad
      plt.imshow(img[0])
      plt.savefig('output/'+str(i+1)+'.png')
      plt.close('all')
  </code></pre>
  
  <p>But even after running this loop for 100 iterations the resulting picture still looks random (I will attach said picture to this Question). 
  <a href="https://i.stack.imgur.com/zZsK1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zZsK1.png" alt="enter image description here"></a>Can someone please help me to optimize my code?</p>