Training deep neural networks for binary communication with the Whetstone method

The computational cost of deep neural networks presents challenges to broadly deploying these algorithms. Low-power and embedded neuromorphic processors offer potentially dramatic performance-per-watt improvements over traditional processors. However, programming these brain-inspired platforms generally requires platform-specific expertise. It is therefore difficult to achieve state-of-the-art performance on these platforms, limiting their applicability. Here we present Whetstone, a method to bridge this gap by converting deep neural networks to have discrete, binary communication. During the training process, the activation function at each layer is progressively sharpened towards a threshold activation, with limited loss in performance. Whetstone sharpened networks do not require a rate code or other spike-based coding scheme, thus producing networks comparable in timing and size to conventional artificial neural networks. We demonstrate Whetstone on a number of architectures and tasks such as image classification, autoencoders and semantic segmentation. Whetstone is currently implemented within the Keras wrapper for TensorFlow and is widely extendable.