Octal gray-code phase unwrapping for high-speed fringe projection profilometry

• Main Authors: He, Xiaoyu, Zheng, Dongliang, Qian, Kemao
• Other Authors: Interdisciplinary Graduate School (IGS)
• Format: Conference or Workshop Item
• Language: English
• Published: 2019
• Subjects: Phase Unwrapping; Octal Gray Code; DRNTU::Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/87631; http://hdl.handle.net/10220/47663
• Institution: Nanyang Technological University

The speed of a fringe projection profilometry system is of great importance for the measurement of dynamic objects. The previous quaternary gray-code phase unwrapping method uses only five patterns to recover an absolute phase which is suitable for high-speed measurement. However, this method requires a pre-knowledge of the minimum depth and it limits the object to move in a small range of depth. To extend the measurement range, we proposed an octal gray-code phase unwrapping method, in which five patterns are required. We apply this method to different objects and analysis the experiment results. This method can recover a good-quality phase map for sample objects, while its performance is decreased when the object is complex or with an improper defocusing level.