Robust self-calibration three-dimensional shape measurement in fringe-projection photogrammetry

Area of Science:

• Optics and Photonics
• Computer Vision
• Metrology

Background:

• Fringe-projection photogrammetry typically uses independent calibration and measurement stages.
• Measurement accuracy is highly sensitive to calibration stability, which can be problematic.
• Existing methods may lack robustness in real-world calibration scenarios.

Purpose of the Study:

• To develop a robust self-calibration method for fringe-projection 3D shape measurement.
• To improve the stability and accuracy of 3D measurements in photogrammetry.
• To leverage photogrammetry's multi-view capabilities for enhanced fringe-projection techniques.

Main Methods:

• A novel self-calibration approach combining known 3D control points and absolute phase measurement points.
• Utilizing nonlinear collinearity equations with invariant control points for robust optimization.
• Employing multiple-view ray intersection, a core photogrammetry principle, for 3D reconstruction.

Main Results:

• Demonstrated enhanced measurement robustness through the invariant nature of control points.
• Achieved stable and accurate 3D shape measurements by overcoming calibration instabilities.
• Showcased the advantage of multi-view ray intersection over traditional binocular models in this technique.

Conclusions:

• The proposed robust self-calibration method significantly improves fringe-projection photogrammetry.
• Integrating control points enhances the reliability and accuracy of 3D shape measurement systems.
• Multi-view ray intersection offers superior performance for 3D reconstruction in fringe-projection techniques.