A Linear Comb Filter for Event Flicker Removal
This addresses a specific noise issue for robotics applications using event cameras in indoor or flickering-light environments, representing an incremental improvement in preprocessing.
The paper tackles the problem of event cameras being sensitive to flicker from lights like fluorescents, which generates noise events that swamp useful data for robotics, by proposing a novel linear filter that removes these events and achieves over 4.6 times relative improvement in signal-to-noise ratio.
Event cameras are bio-inspired sensors that capture per-pixel asynchronous intensity change rather than the synchronous absolute intensity frames captured by a classical camera sensor. Such cameras are ideal for robotics applications since they have high temporal resolution, high dynamic range and low latency. However, due to their high temporal resolution, event cameras are particularly sensitive to flicker such as from fluorescent or LED lights. During every cycle from bright to dark, pixels that image a flickering light source generate many events that provide little or no useful information for a robot, swamping the useful data in the scene. In this paper, we propose a novel linear filter to preprocess event data to remove unwanted flicker events from an event stream. The proposed algorithm achieves over 4.6 times relative improvement in the signal-to-noise ratio when compared to the raw event stream due to the effective removal of flicker from fluorescent lighting. Thus, it is ideally suited to robotics applications that operate in indoor settings or scenes illuminated by flickering light sources.