Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslávských Partyzánů 1580/3, 160 00 Prague, Czech Republic.
Department of Weapons and Ammunition, Faculty of Military Technology, University of Defence, Kounicova 65, 662 10 Brno, Czech Republic.
Sensors (Basel). 2021 Feb 6;21(4):1137. doi: 10.3390/s21041137.
We compare event-cameras with fast (global shutter) frame-cameras experimentally, asking: "What is the application domain, in which an event-camera surpasses a fast frame-camera?" Surprisingly, finding the answer has been difficult. Our methodology was to test event- and frame-cameras on generic computer vision tasks where event-camera advantages should manifest. We used two methods: (1) a controlled, cheap, and easily reproducible experiment (observing a marker on a rotating disk at varying speeds); (2) selecting one challenging practical ballistic experiment (observing a flying bullet having a ground truth provided by an ultra-high-speed expensive frame-camera). The experimental results include sampling/detection rates and position estimation errors as functions of illuminance and motion speed; and the minimum pixel latency of two commercial state-of-the-art event-cameras (ATIS, DVS240). Event-cameras respond more slowly to positive than to negative large and sudden contrast changes. They outperformed a frame-camera in bandwidth efficiency in all our experiments. Both camera types provide comparable position estimation accuracy. The better event-camera was limited by pixel latency when tracking small objects, resulting in motion blur effects. Sensor bandwidth limited the event-camera in object recognition. However, future generations of event-cameras might alleviate bandwidth limitations.
我们通过实验将事件相机与高速(全局快门)帧相机进行了比较,提出了一个问题:“在哪个应用领域,事件相机优于高速帧相机?”令人惊讶的是,要找到答案并不容易。我们的方法是在通用计算机视觉任务上测试事件相机和帧相机,这些任务中应该会表现出事件相机的优势。我们使用了两种方法:(1)控制、廉价且易于复制的实验(观察旋转磁盘上以不同速度旋转的标记);(2)选择一个具有挑战性的实际弹道实验(观察具有地面真实数据的飞行子弹,地面真实数据由昂贵的高速帧相机提供)。实验结果包括采样/检测率以及位置估计误差作为照度和运动速度的函数;以及两款商业最先进的事件相机(ATIS、DVS240)的最小像素延迟。相对于负向的大而突然的对比度变化,事件相机对正向的变化响应更慢。在我们的所有实验中,事件相机在带宽效率方面都优于帧相机。两种相机类型提供相当的位置估计精度。在跟踪小物体时,性能更好的事件相机受到像素延迟的限制,导致运动模糊效果。传感器带宽限制了事件相机在目标识别方面的性能。然而,未来几代的事件相机可能会缓解带宽限制。