Large depth-of-field 3D shape measurement using an electrically tunable lens.
OPTICS EXPRESS(2019)
摘要
The state-of-the-art 3D shape measurement system has rather shallow working volume due to the limited depth-of-field (DOF) of conventional lens. In this paper, we propose to use the electrically tunable lens to substantially enlarge the DOF. Specifically, we capture always in-focus phase-shifted fringe patterns by precisely synchronizing the tunable lens attached to the camera with the image acquisition and the pattern projection; we develop a phase unwrapping framework that fully utilizes the geometric constraint from the camera focal length setting; and we pre-calibrate the system under different focal distance to reconstruct 3D shape from unwrapped phase map. To validate the proposed idea, we developed a prototype system that can perform high-quality measurement for the depth range of approximately 1,000 mm (400 mm - 1400 mm) with the measurement error of 0.05%. Furthermore, we demonstrated that such a technique can be used for real-time 3D shape measurement by experimentally measuring moving objects. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络