Calibration based on ray-tracing for multi-line structured light projection system.

Area of Science:

• Computer Vision
• Optical Metrology
• 3D Reconstruction

Background:

• Multi-line Structured Light Projection Systems (MSLPS) offer advantages in high-speed dynamic 3D reconstruction over Phase Modulation Systems (PMS).
• Existing MSLPS calibration methods are often complex or lack accuracy, especially in large visual fields, due to lens distortion and the need for projector calibration.

Purpose of the Study:

• To develop an accurate and robust calibration method for MSLPS that simplifies the process and improves 3D reconstruction.
• To establish a direct relationship between 2D image coordinates and 3D world coordinates without projector calibration.

Main Methods:

• A novel ray-tracing calibration technique is proposed.
• The method establishes an accurate relationship between subpixel coordinates of bending line structured light planes and 3D coordinates within the camera's coordinate system.
• Calibration is performed using a standard checkerboard target placed at random positions.

Main Results:

• The proposed ray-tracing method achieves accurate and robust 3D reconstruction.
• It demonstrates superior performance compared to existing line structured light calibration strategies.
• The calibration process is significantly simpler and easier to implement.

Conclusions:

• The developed ray-tracing calibration method offers a more practical and accurate solution for MSLPS.
• It effectively addresses the limitations of existing methods, particularly for large visual field applications.
• The simplified calibration procedure enhances the suitability of MSLPS for real-world applications.