title: Machine learning: how to identify if there is no object of trained classes in image
body: <p>if I train a deep neural network with (say) 10 classes and I feed the network a completely different image, is it reasonable to expect that the output layer's cells will not activate much, so I will know there is no object of the trained classes in the image?</p>
  
  <p>My intuition says "Yes", but is it so? And what would be the best approach to this?</p>
  
  <p>Thanks</p>