Improved phase-unwrapping method using geometric constraints. Issue 13 (20th July 2017)

• Record Type: Journal Article
• Authors: Du, Guangliang; Wang, Minmin; Zhou, Canlin; Si, Shuchun; Li, Hui; Lei, Zhenkun; Li, Yanjie
• Is Part Of: Journal of modern optics. Volume 64:Issue 13(2017)
• Page Start: 1263
• Page End: 1269
• Publication Date: 2017-07-20
• Subjects: Phase unwrapping -- geometric constraints -- dual-frequency; Optics -- Periodicals; 535
• DOI: 10.1080/09500340.2017.1284279
• Languages: English
• ISSNs: 0950-0340

Abstract

Abstract: Conventional dual-frequency fringe projection algorithm often suffers from phase unwrapping failure when the frequency ratio between the high frequency and the low one is too large. Zhang et al. proposed an enhanced two-frequency phase-shifting method to use geometric constraints of digital fringe projection (DFP) to reduce the noise impact due to the large frequency ratio. However, this method needs to calibrate the DFP system and calculate the minimum phase mapφ min at the nearest position from the camera perspective, these procedures are relatively complex and more time-consuming. In this paper, we proposed an improved method, which eliminates the system calibration andφ min determination in Zhang's method, meanwhile does not need to use the low-frequency fringe pattern. In the proposed method, we only need a set of high-frequency fringe patterns to measure the object after the high frequencyφ min is directly estimated by the experiment. Thus, the proposed method can simplify the procedure and improve the speed. Finally, the experimental evaluation is conducted to prove the validity of the proposed method. The results demonstrate that the proposed method can overcome the main disadvantages encountered by Zhang's method.