High-speed three-dimensional profilometry for multiple objects with complex shapes

• Published in: Optics express 2012-08, Vol.20 (17), p.19493-19510
• Main Authors: Zuo, Chao, Chen, Qian, Gu, Guohua, Feng, Shijie, Feng, Fangxiaoyu
• Format: Article
• Language: English
• Subjects: Algorithms; Artificial Intelligence; Image Enhancement - methods; Image Interpretation, Computer-Assisted - methods; Imaging, Three-Dimensional - methods; Pattern Recognition, Automated - methods; Reproducibility of Results; Sensitivity and Specificity
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.20.019493

This paper describes an easy-to-implement three-dimensional (3-D) real-time shape measurement technique using our newly developed high-speed 3-D vision system. It employs only four projection fringes to realize full-field phase unwrapping in the presence of discontinuous or isolated objects. With our self-designed pattern generation hardware and a modified low-cost DLP projector, the four designed patterns can be generated and projected at a switching speed of 360 Hz. Using a properly synchronized high-speed camera, the high-speed fringe patterns distorted by measured objects can be acquired and processed in real-time. The resulting system can capture and display high-quality textured 3-D data at a speed of 120 frames per second, with the resolution of 640 × 480 points. The speed can be trebled if a camera with a higher frame rate is employed. We detail our shape measurement technique, including the four-pattern decoding algorithm as well as the hardware design. Some evaluation experiments have been carried out to demonstrate the validity and practicability of the proposed technique.