Flexible calibration method for microscopic structured light system using telecentric lens.

Area of Science:

• Metrology
• Optical Engineering
• Computer Vision

Background:

• Microscopic 3D measurement systems require precise calibration for accurate results.
• Structured light systems are widely used for 3D reconstruction but can be challenging to calibrate accurately, especially at microscopic scales.
• Telecentric lenses offer advantages in microscopic imaging by minimizing perspective distortion, but their integration into calibration procedures needs careful consideration.

Purpose of the Study:

• To present a novel and accurate calibration method for a microscopic structured light system.
• To integrate a camera with a telecentric lens into the structured light calibration framework.
• To achieve high-precision 3D coordinate measurements within a defined microscopic volume.

Main Methods:

• The proposed method calibrates the projector using standard pin-hole camera calibration procedures.
• Iterative Levenberg-Marquardt optimization is employed to estimate 3D coordinates of feature points.
• A mathematical model for a telecentric lens is utilized for camera calibration.

Main Results:

• The developed calibration framework demonstrates very high accuracy.
• Achieved accuracy is approximately 10 micrometers.
• The system successfully calibrated for a measurement volume of approximately 10 mm (H) x 8 mm (W) x 5 mm (D).

Conclusions:

• The novel calibration method provides a robust solution for microscopic structured light systems.
• The integration of telecentric lens cameras enhances measurement accuracy and precision.
• This research contributes to advancements in high-accuracy 3D metrology at microscopic scales.