All-telecentric multi-camera microscopic FPP: Scheimpflug calibration and reprojection-based multi-view fusion

Area of Science:

• Metrology
• Optical Engineering
• Microscopy

Background:

• Microscopic fringe projection profilometry (MFPP) is crucial for 3D reconstruction at the microscale.
• Single-view MFPP struggles with complex specimens due to self-occlusion and specular saturation, limiting accuracy and completeness.
• Existing multi-view systems often face challenges with calibration and data fusion.

Purpose of the Study:

• To develop an advanced all-telecentric multi-camera MFPP system for improved microscopic 3D measurements.
• To introduce a robust calibration pipeline and a phase-consistent fusion strategy for enhanced reconstruction.
• To address the limitations of conventional MFPP on complex and occluded micro-scale structures.

Main Methods:

• An all-telecentric system with a vertical projector and four oblique Scheimpflug telecentric cameras.
• A novel calibration pipeline involving projection matrix fitting, decomposition, and bundle-adjusted joint calibration.
• Phase-consistent reprojection for cross-view correspondence and modulation-weighted fusion with adaptive mismatch rejection for reconstruction.

Main Results:

• The proposed system demonstrates superior measurement completeness and consistency compared to single-view and conventional multi-view methods.
• The joint calibration approach effectively mitigates ill-conditioning and scale drift.
• The fusion strategy successfully preserves observation quality, reduces bias, and fills visibility gaps while maintaining boundary fidelity.

Conclusions:

• The all-telecentric multi-camera MFPP system, coupled with the proposed calibration and fusion techniques, provides accurate and robust 3D microscale measurements.
• This approach significantly improves the ability to reconstruct complex specimens, overcoming typical occlusion and saturation issues.
• The developed methodology offers a promising solution for high-fidelity 3D imaging in microscopic applications.