A. Ingle, A. Gupta, A. Velten, M. Gupta
University of Wisconsin-Madison,
Keywords: single-photon sensors, LiDAR, 3D cameras
Summary:Single-photon cameras are an exciting new image sensor technology with the unique ability to operate in extremely low light levels down to individual photons. In addition to their extreme sensitivity, these sensors can precisely measure the time-of-arrival of photons with very high accuracy of tens of picoseconds. This makes single-photon cameras ideal candidates for high-resolution long-range 3D imaging. They can potentially provide “laser-scan-quality” 3D scans of objects at >100 meters away. However, single-photon 3D cameras can work reliably only in low light. Due to their peculiar operation method, these cameras suffer from severe non-linear distortions when operated outdoors under bright ambient illumination (e.g. sunlight), resulting in large errors in the estimated 3D depths. We design optimal image acquisition techniques that rely on a combination of optical (hardware) and computational approaches that mitigate the distortion from ambient light and can generate 3D reconstructions with unprecedented accuracy even at long distances. We demonstrate a proof-of-concept single-photon 3D camera that can operate in extreme ambient illumination of over 20,000 lux, providing almost an order of magnitude improvement in depth accuracy compared to state-of-the-art. This technology will have implications for a wide variety of 3D imaging applications including LiDARs for autonomous vehicles, low-power and high-speed 3D cameras for robotics, and high-resolution airborne LiDARs used in geospatial surveys.