Event-Based Imaging with Active Illumination in Sensor Networks

We discuss a distributed imaging architecture with active illumination for sensor network applications. An event-based CMOS imager is employed at the sensor level, to convert light intensity at each pixel into a pulse density modulated stream of address events. The wireless nodes are commercial off-the-shelf motes. Energy-aware communication is implemented at the sensor level by employing an event-based readout. Additional computation for data reduction is accomplished at the sensor/mote interface level by modulating the event-rate produced by the sensor array to match the bandwidth and latency constraints in the communication network. Information transmitted in the limited bandwidth links of the network yields effective means for detection and partial recognition of the object, even at very low bit rates and frame latency as low as 1s.