title: Error converting Facenet model .pb file to TFLITE format
body: <p>i'm trying to convert a pre-trained frozen .pb based on Inception ResNet i got from <a href="https://github.com/davidsandberg/facenet" rel="nofollow noreferrer">David Sandbergs Github</a> with the Tensorflow Lite Converter on Ubuntu using the following command:</p>
  
  <pre><code>/home/nils/.local/bin/tflite_convert
  --output_file=/home/nils/Documents/frozen.tflite
  --graph_def_file=/home/nils/Documents/20180402-114759/20180402-114759.pb 
  --input_arrays=input 
  --output_arrays=embeddings 
  --input_shapes=1,160,160,3
  </code></pre>
  
  <p>However, i get the following error:</p>
  
  <pre><code>2018-12-03 15:03:16.807431: I tensorflow/core/platform/cpu_feature_guard.cc:141] Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX2
  Traceback (most recent call last):
  File "/home/nils/.local/bin/tflite_convert", line 11, in &lt;module&gt;
  sys.exit(main())
  File "/home/nils/.local/lib/python3.6/site-packages/tensorflow/contrib/lite/python/tflite_convert.py", line 412, in main
  app.run(main=run_main, argv=sys.argv[:1])
  File "/home/nils/.local/lib/python3.6/site-packages/tensorflow/python/platform/app.py", line 125, in run
  _sys.exit(main(argv))
  File "/home/nils/.local/lib/python3.6/site-packages/tensorflow/contrib/lite/python/tflite_convert.py", line 408, in run_main
  _convert_model(tflite_flags)
  File "/home/nils/.local/lib/python3.6/site-packages/tensorflow/contrib/lite/python/tflite_convert.py", line 162, in _convert_model
  output_data = converter.convert()
  File "/home/nils/.local/lib/python3.6/site-packages/tensorflow/contrib/lite/python/lite.py", line 453, in convert
  **converter_kwargs)
  File "/home/nils/.local/lib/python3.6/site-packages/tensorflow/contrib/lite/python/convert.py", line 342, in toco_convert_impl
  input_data.SerializeToString())
  File "/home/nils/.local/lib/python3.6/site-packages/tensorflow/contrib/lite/python/convert.py", line 135, in toco_convert_protos
  (stdout, stderr))
  RuntimeError: TOCO failed see console for info.
  b'2018-12-03 15:03:26.006252: I tensorflow/contrib/lite/toco/import_tensorflow.cc:1080] Converting unsupported operation: FIFOQueueV2\n2018-12-03 15:03:26.006322: I tensorflow/contrib/lite/toco/import_tensorflow.cc:1127] Op node missing output type attribute: batch_join/fifo_queue\n2018-12-03 15:03:26.006339: I tensorflow/contrib/lite/toco/import_tensorflow.cc:1080] Converting unsupported operation: QueueDequeueUpToV2\n2018-12-03 15:03:26.006352: I tensorflow/contrib/lite/toco/import_tensorflow.cc:1127] Op node missing output type attribute: batch_join\n2018-12-03 15:03:27.496676: I tensorflow/contrib/lite/toco/graph_transformations/graph_transformations.cc:39] Before Removing unused ops: 5601 operators, 9399 arrays (0 quantized)\n2018-12-03 15:03:28.603936: I tensorflow/contrib/lite/toco/graph_transformations/graph_transformations.cc:39] After Removing unused ops pass 1: 3578 operators, 6254 arrays (0 quantized)\n2018-12-03 15:03:29.418074: I tensorflow/contrib/lite/toco/graph_transformations/graph_transformations.cc:39] Before general graph transformations: 3578 operators, 6254 arrays (0 quantized)\n2018-12-03 15:03:29.420354: F tensorflow/contrib/lite/toco/graph_transformations/resolve_batch_normalization.cc:42] 
  Check failed: IsConstantParameterArray(*model, bn_op-&gt;inputs[1]) &amp;&amp; IsConstantParameterArray(*model, bn_op-&gt;inputs[2]) &amp;&amp; IsConstantParameterArray(*model, bn_op-&gt;inputs[3]) Batch normalization resolution requires that mean, multiplier and offset arrays be constant.\nAborted (core dumped)\n'
  None
  </code></pre>
  
  <p>If i get this right, this might be because of two unsupported Ops, QueueDequeueUpToV2 and FIFOQueueV2, but i don't know for sure. 
  Do you have any ideas what might be the problem or how i can solve this error? What does that error even mean? I want this model to run on a mobile android device, are there any alternatives? 
  Versions: 
  Tensorflow V1.12
  Python 3.6.7
  Ubuntu 18.04.1 LTS
  on a VirtualBox
  Thanks in advance!</p>