Pixel-by-pixel absolute phase retrieval assisted by an additional three-dimensional scanner

This paper presents a novel absolute phase unwrapping method assisted by a low-cost three-dimensional (3D) scanner. The proposed absolute phase unwrapping method leverages a low-cost 3D scanner to capture rough 3D data of the scene and transforms the rough 3D data to the world coordinate system to generate an artificial reference phase map ϕ_ref. By referring to ϕ_ref, we can do absolute phase unwrapping directly without projecting any additional patterns, such that the digital fringe projection (DFP) system can achieve higher measurement speed. We develop a multiresolution system consisting of a DFP system and a Kinect V2 to validate our method. Experiments demonstrate that our method works for a large depth range, and the speed of the low-cost 3D scanner is not necessarily the maximum speed of our proposed method. Assisted by the Kinect V2, whose maximum speed is only 30 Hz, our DFP system achieves 53 Hz with a resolution 1600×1000 pixels when we measure dynamic objects that are moving in a large depth range of 400 mm.