Keyhole Imaging: Non-Line-of-Sight Imaging and Tracking of Moving Objects Along a Single Optical Path

Non-line-of-sight (NLOS) imaging and tracking is an emerging technology that allows the shape or position of objects around corners behind diffusers to be recovered from transient, time-of-flight measurements. However, existing NLOS approaches require system scan a large area on visible surface, where indirect light paths hidden are sampled. In many applications, such as robotic vision autonomous driving, optical access scanning may not available, which severely limits practicality techniques. Here, we propose new approach, dubbed keyhole imaging, captures sequence transient measurements along single path, for example, through keyhole. Assuming object interest moves during acquisition time, effectively capture series time-resolved projections object's unknown viewpoints. We derive inverse methods based expectation-maximization recover location using these Then, with help long exposure times retroreflective tape, demonstrate successful experimental results prototype system.