Calibration of a Structured Light Imaging System in Two-Layer Flat Refractive Geometry for Underwater Imaging

Area of Science:

• Computer Vision
• Optical Engineering
• Robotics

Background:

• Underwater 3D imaging systems face challenges due to environmental factors.
• System calibration is critical for accurate 3D reconstruction.
• Existing calibration methods can be computationally intensive and complex.

Purpose of the Study:

• To develop a novel and robust calibration method for underwater 3D imaging systems.
• To address the limitations of current calibration techniques for systems with shared glass interfaces.
• To improve the accuracy and efficiency of 3D reconstruction in underwater environments.

Main Methods:

• A novel calibration method for a 3D imaging system with cameras, a projector, and a shared glass interface.
• Utilizing the axial camera model for image formation.
• Employing numerical optimization of a 3D cost function to determine system parameters, avoiding complex polynomial equation solving.
• A stable approach for estimating the axial camera model's axis.

Main Results:

• The proposed calibration method was experimentally validated on four different glass interfaces.
• Achieved a mean angular error of under 6° for the system's axis.
• Demonstrated mean absolute errors of 1.38 mm (normal glass) and 2.82 mm (laminated glass) for flat surface reconstruction.

Conclusions:

• The novel calibration method provides accurate and efficient parameter determination for underwater 3D imaging systems.
• The method is suitable for various glass interfaces, offering high precision for 3D reconstruction.
• This advancement facilitates more reliable underwater 3D imaging applications.