Depth-of-field extension method for telecentric structured light based on dual-viewpoint stitching

Area of Science:

• Optics and Photonics
• Metrology and Measurement Science

Background:

• Structured light techniques are crucial for high-precision 3D reconstruction and measurement.
• Traditional telecentric systems face depth-of-field (DOF) limitations hindering large-scale height reconstruction.

Purpose of the Study:

• To propose and validate a dual-viewpoint stitching method for extending the DOF of telecentric structured light systems.
• To enable large-scale height reconstruction without compromising measurement accuracy.

Main Methods:

• Implemented a dual-viewpoint system with vertically shifted cameras to capture data at different heights within a common focal region.
• Developed a pre-calibrated point cloud stitching method utilizing telecentric lens geometric consistency.
• Used a determined stitching matrix to merge point clouds from different viewpoints, eliminating the need for feature-based registration.

Main Results:

• Achieved a 1.7-fold extension of the DOF range for the telecentric system.
• Maintained high measurement precision with relative errors within 0.12% for repeated measurements.
• Demonstrated significantly improved stitching efficiency and engineering applicability.

Conclusions:

• The dual-viewpoint stitching method effectively extends the DOF of telecentric structured light systems.
• The approach preserves high measurement accuracy and enhances stitching efficiency for large-scale 3D reconstruction.
• The method offers a practical solution for applications requiring extended depth imaging with precision.