title: How to use keras ImageDataGenerator with a Siamese or Tripple networks
body: <p>I'm trying to build up both a Siamese neural network and <a href="https://arxiv.org/pdf/1412.6622v3.pdf" rel="noreferrer">triple neural network</a>  on a custom large dataset</p>
  
  <p><code>Keras</code> has <code>ImageDataGenerator</code> which makes the generation of input data to a <code>regular</code> neural network very easy. </p>
  
  <p>I'm interesting to use <code>ImageDataGenerator</code> or similar ways in order to train a networks with 2(<code>siamese</code>) and 3(<code>triple</code>)  inputs.</p>
  
  <p>In <a href="https://github.com/fchollet/keras/blob/master/examples/mnist_siamese_graph.py" rel="noreferrer">mniset keras siamese example</a>, The input generated by a pre-process stage which is done by <code>create_pairs</code> method. I don't think this kind of way fit for a large dataset.</p>
  
  <p>Is it possible to use <code>ImageDataGenerator</code> in this case? What are my other options assuming the data-set is very big?</p>