  Event cameras are bio-inspired sensors that respond to per-pixel brightness
changes in the form of asynchronous and sparse "events". Recently, pattern
recognition algorithms, such as learning-based methods, have made significant
progress with event cameras by converting events into synchronous dense,
image-like representations and applying traditional machine learning methods
developed for standard cameras. However, these approaches discard the spatial
and temporal sparsity inherent in event data at the cost of higher
computational complexity and latency. In this work, we present a general
framework for converting models trained on synchronous image-like event
representations into asynchronous models with identical output, thus directly
leveraging the intrinsic asynchronous and sparse nature of the event data. We
show both theoretically and experimentally that this drastically reduces the
computational complexity and latency of high-capacity, synchronous neural
networks without sacrificing accuracy. In addition, our framework has several
desirable characteristics: (i) it exploits spatio-temporal sparsity of events
explicitly, (ii) it is agnostic to the event representation, network
architecture, and task, and (iii) it does not require any train-time change,
since it is compatible with the standard neural networks' training process. We
thoroughly validate the proposed framework on two computer vision tasks: object
detection and object recognition. In these tasks, we reduce the computational
complexity up to 20 times with respect to high-latency neural networks. At the
same time, we outperform state-of-the-art asynchronous approaches up to 24% in
prediction accuracy.
