SEpi-3D: soft epipolar 3D shape measurement with an event camera for multipath elimination

Multipath in 3D imaging happens when one pixel receives light from multiple reflections, which causes errors in the measured point cloud. In this paper, we propose the soft epipolar 3D(SEpi-3D) method to eliminate multipath in temporal space with an event camera and a laser projector. Specifically, we align the projector and event camera row onto the same epipolar plane with stereo rectification; we capture event flow synchronized with the projector frame to construct a mapping relationship between event timestamp and projector pixel; we develop a multipath eliminating method that utilizes the temporal information from the event data together with the epipolar geometry. Experiments show that the RMSE decreases by 6.55mm on average in the tested multipath scenes, and the percentage of error points decreases by 7.04%.