Training Quantized Neural Networks

Introduction

Train your own Quantized Neural Networks (QNN) - networks trained with quantized weights and activations - in Keras / Tensorflow. If you use this code, please cite "B.Moons et al. "Minimum Energy Quantized Neural Networks", Asilomar Conference on Signals, Systems and Computers, 2017". Take a look at our presentation or at the paper on arxiv.

This code is based on a lasagne/theano and a Keras/Tensorflow version of BinaryNet.

Preliminaries

Running this code requires:

1. Tensorflow
2. Keras 2.0
3. pylearn2 + the correct PYLEARN2_DATA_PATH in ./personal_config/shell_source.sh
4. A GPU with recent versions of CUDA and CUDNN
5. Correct paths in ./personal_config/shell_source.sh

Make sure your backend='tensorflow' and image_data_format='channels_last' in the ~/.keras/keras.json file.

Training your own QNN

This repo includes toy examples for CIFAR-10 and MNIST. Training can be done by running the following:

./train.sh <config_file> -o <override_parameters>

-o overrides parameters in the <config_file>.

The following parameters are crucial:

• network_type: 'float', 'qnn', 'full-qnn', 'bnn', 'full-bnn'
• wbits, abits: the number of bits used for weights and activations
• lr: the used learning rate. 0.01 is a typical good starting point
• dataset, dim, channels: variables depending on the used dataset
• nl<>: the number of layers in block A, B, C
• nf<>: the number of filters in block A, B, C

Examples

• This is how to train a 4-bit full qnn on CIFAR-10:

  ./train.sh config_CIFAR-10 -o lr=0.01 wbits=4 abits=4 network_type='full-qnn'

• This is how to train a qnn with 4-bit weights and floating point activations on CIFAR-10:

  ./train.sh config_CIFAR-10 -o lr=0.01 wbits=4 network_type='qnn'

• This is how to train a BinaryNet on CIFAR-10:

  ./train.sh config_CIFAR-10 -o lr=0.01 network_type='full-bnn'

---

The included networks have parametrized sizes and are split into three blocks (A-B-C), each with a number of layers (nl) and a number of filters per layer (nf).

• This is how to train a small 2-bit network on MNIST:

  ./train.sh config_MNIST -o nla=1 nfa=64 nlb=1 nfb=64 nlc=1 nfc=64 wbits=2 abits=2 network_type='full-qnn'

• This is how to train a large 8-bit network on CIFAR-10:

  ./train.sh config_CIFAR-10 -o nla=3 nfa=256 nlb=3 nfb=256 nlc=3 nfc=256 wbits=8 abits=8 network_type='full-qnn'