Spatial-temporal multiplexed phase coding with self-synthesized fringe-order correction for high-speed 3D shape...

Area of Science:

• Optics and Photonics
• Computer Vision
• Metrology

Background:

• Conventional temporal phase unwrapping (TPU) in fringe projection profilometry (FPP) is limited in dynamic environments due to the need for multiple encoded fringe patterns.
• Real-time 3D shape measurement demands efficient phase unwrapping techniques that minimize data acquisition and processing time.

Purpose of the Study:

• To develop a novel FPP framework for high-efficiency and high-accuracy 3D shape measurement in dynamic environments.
• To overcome the limitations of conventional TPU methods in real-time applications.

Main Methods:

• Introduced a spatial-temporal multiplexed phase-coding strategy using two complementary phase-coded patterns for dense fringe-order encoding.
• Developed a self-synthesized complementary fringe-order correction algorithm employing half-period spatial shifting and wrapped phase analysis.
• Utilized gradient-constrained local optimization for artifact suppression without additional projections.

Main Results:

• Successfully decoupled background intensity and modulation amplitude from phase-shifted components.
• Enabled absolute phase reconstruction using only four projected images for dynamic measurement and five for static scenarios.
• Demonstrated suppression of phase-jump errors at geometric discontinuities and under motion artifacts.

Conclusions:

• The proposed FPP framework significantly enhances real-time 3D reconstruction performance.
• The novel phase-coding and correction strategy allows for accurate 3D shape measurement in challenging dynamic environments.
• This advancement has potential applications in industrial inspection and biomedical imaging.