Margin-Aware Binarized Weight Networks for Image Classification

Ting-Bing Xu, Peipei Yang, Xu-Yao Zhang, Cheng-Lin Liu

Abstract: Deep neural networks (DNNs) have achieved remarkable successes in many vision tasks. However, due to the dependence on large memory and high-performance GPUs, it is extremely hard to deploy DNNs on low-power devices. For compressing and accelerating deep neural networks, many techniques have been proposed recently. Particularly, binarized weight networks, which store one weight using only one bit and replace complex floating operations with simple calculations, are attractive from the perspective of hardware implementation. In this paper, we propose a simple strategy to learn better binarized weight networks. Motivated by the phenomenon that the stochastic binarization approach usually converges with real-valued weights close to two boundaries $$\{-1, +1\}$$ and gives better performance than deterministic binarization, we construct a margin-aware binarization strategy by adding a weight constraint into the objective function of deterministic scheme to minimize the margins between real-valued weights and boundaries. This constraint can be easily realized by a Binary-L2 regularization without suffering from the complex random number generation. Experimental results on MNIST and CIFAR-10 datasets show that the proposed method yields better performance than recent network binarization schemes and the full precision network counterpart.