Abstract

Dynamic Vision Sensors (DVS) record 'events' corresponding to pixel-level brightness changes, resulting in data-efficient representation of a dynamic visual scene. As DVS expand into increasingly diverse applications, non-ideal behaviors in their output under extreme sensing conditions are important to consider. Under low illumination (below ≈10 lux), their output begins to be dominated by shot noise events (SNEs) which increase the data output and obscure true signal. SNE rates can be controlled to some degree by tuning circuit parameters to reduce sensitivity or temporal response bandwidth at the cost of signal loss. Alternatively, an improved understanding of SNE statistics can be leveraged to develop novel techniques for minimizing uninformative sensor output. This work explains a fundamental observation about sequential pairing of opposite polarity SNEs based on pixel circuit logic and validates this theory using DVS recordings and simulations. It derives a practical result from this new understanding and demonstrates two novel biasing techniques shown to reduce SNEs by 50% and 80% respectively while still retaining sensitivity and/or temporal resolution.