H-Direct: Homeostasis-aware Direct Spike Encoding for Deep Spiking Neural Networks

Abstract

Deep spiking neural networks (SNNs), gaining attention as the next generation of artificial neural networks, have been successfully applied to many applications thanks to the development of various algorithms, such as spike encoding. Spike encoding represents input information as discrete spikes, significantly influencing the performance and efficiency of deep SNNs. Most state-of-the-art deep SNN models have greatly improved their performance by using direct encoding. However, performance and efficiency have been limited by the lack of consideration for the brain’s efficiency mechanisms, such as homeostasis. To overcome this limitation, we propose H-Direct, a spike encoding technique designed to balance both effectiveness and efficiency, based on a comprehensive analysis of conventional direct encoding. Furthermore, experimental results confirm that our proposed encoding surpasses traditional direct encoding in both performance and efficiency across multiple image classification benchmarks.