retrain.py is an example script that shows how one can adapt a pretrained network for other classification problems. A detailed overview of this script can be found at: https://www.tensorflow.org/tutorials/image_retraining
The script also shows how one can train layers with quantized weights and activations instead of taking a pre-trained floating point model and then quantizing weights and activations. The output graphdef produced by this script is compatible with the TensorFlow Lite Optimizing Converter and can be converted to TFLite format.