Abstract

A phase unwrapping method for phase-shifting projected fringe profilometry is presented. It did not require additional projections to identify the fringe orders. The pattern used for the phase extraction could be used for phase unwrapping directly. By spatially encoding the fringe patterns that were used to perform the phase-shifting technique with binary contrasts, fringe orders could be discerned. For spatially isolated objects or surfaces with large depth discontinuities, unwrapping could be identified without ambiguity. Even though the surface color or reflectivity varied periodically with position, it distinguished the fringe order very well.

Highlights

  • Phase-shifting projected fringe profilometry is a powerful tool in many profiling applications [1,2,3,4,5]

  • The binary-encoded patterns whose 1D gray-level distributions are shown in Figure 3 were projected onto the calibration tool by the digital projector (Epson EB-U04, with a resolution of 1920 × 1200)

  • A set of binary-encoded fringe patterns was presented for phase-shifting fringe projection profilometry

Read more

Summary

Introduction

Phase-shifting projected fringe profilometry is a powerful tool in many profiling applications [1,2,3,4,5]. It sequentially projects a set of single-frequency patterns in which one differs from the others with a known shifted phase onto the inspected object. The sequent projections on the inspected surface are recorded using an image sensor array from another view angle. The phase of the projected fringes is distorted by the surface profile and, the retrieved surface profile is analyzable. In the task of phase extraction, an arctangent operation is employed, making the phase being wrapped modulo 2π. Unwrapping is required to recover the absolute phase distribution

Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call