Event Camera

A camera where each pixel independently outputs an “event” only when brightness changes, instead of capturing full frames.

An event camera is a biologically inspired vision sensor, also called a dynamic vision sensor (DVS) or neuromorphic camera. An ordinary camera outputs a complete image at a fixed frame rate; each pixel in an event camera works independently and asynchronously, firing an event only when its brightness changes past a threshold, with each event carrying the pixel coordinates, a timestamp, and whether it got brighter or darker (polarity). A 2020 survey by Gallego and colleagues in TPAMI summarizes its advantages: microsecond-level time resolution, a dynamic range around 140 dB (versus about 60 dB for ordinary cameras), low power, and almost no motion blur. The tradeoff is that a static scene produces almost no output, and there is no color or absolute brightness information, so it needs dedicated processing algorithms. It suits high-speed motion and scenes with dramatic lighting changes, such as drone obstacle avoidance, high-speed grasping, and visual odometry.

ExampleResearchers at the University of Zurich and ETH Zurich (ICRA 2023) mounted an event camera on a quadruped robot to catch thrown objects, catching items flying in from 4 meters away at up to 15 m/s with an 83% success rate, running the algorithm at 100 Hz on a Jetson Orin.

Also called

Dynamic Vision Sensor, DVS, Neuromorphic Camera, Silicon Retina

Related

RGB Camera · Global Shutter / Rolling Shutter · Visual Odometry · Optical Flow · Exteroception · Multi-Sensor Fusion

Sources

Event-based Vision: A Survey (Gallego et al., TPAMI 2020)
Wikipedia: Event camera
Event-based Agile Object Catching with a Quadrupedal Robot (ICRA 2023)