  Event camera-based pattern recognition is a newly arising research topic in
recent years. Current researchers usually transform the event streams into
images, graphs, or voxels, and adopt deep neural networks for event-based
classification. Although good performance can be achieved on simple event
recognition datasets, however, their results may be still limited due to the
following two issues. Firstly, they adopt spatial sparse event streams for
recognition only, which may fail to capture the color and detailed texture
information well. Secondly, they adopt either Spiking Neural Networks (SNN) for
energy-efficient recognition with suboptimal results, or Artificial Neural
Networks (ANN) for energy-intensive, high-performance recognition. However,
seldom of them consider achieving a balance between these two aspects. In this
paper, we formally propose to recognize patterns by fusing RGB frames and event
streams simultaneously and propose a new RGB frame-event recognition framework
to address the aforementioned issues. The proposed method contains four main
modules, i.e., memory support Transformer network for RGB frame encoding,
spiking neural network for raw event stream encoding, multi-modal bottleneck
fusion module for RGB-Event feature aggregation, and prediction head. Due to
the scarce of RGB-Event based classification dataset, we also propose a
large-scale PokerEvent dataset which contains 114 classes, and 27102
frame-event pairs recorded using a DVS346 event camera. Extensive experiments
on two RGB-Event based classification datasets fully validated the
effectiveness of our proposed framework. We hope this work will boost the
development of pattern recognition by fusing RGB frames and event streams. Both
our dataset and source code of this work will be released at
https://github.com/Event-AHU/SSTFormer.
