Low-distortion perturbative solutions in a camera calibration model including high-distortion radial effects

Area of Science:

• Computer Vision
• Optical Engineering
• Medical Imaging

Background:

• Endoscopic procedures require precise 3D reconstruction.
• Fisheye lenses in endoscopes introduce significant radial distortion.
• Existing calibration models struggle with high distortion levels.

Purpose of the Study:

• To extend endoscope camera calibration models.
• To develop a method for describing lens distortion using intuitive vector parameters.
• To incorporate a fourth-degree radial polynomial for lens distortion.

Main Methods:

• Expanded an existing algorithm for high-distortion endoscopic lenses.
• Decoupled the computation of the camera distortion center.
• Used properties of distortion lines to include radial distortion effects.
• Applied a perturbative approach to a zero-distortion solution.

Main Results:

• Successfully modeled strong radial distortion in fisheye lenses.
• Achieved satisfactory results for endoscope fisheye lenses.
• Maintained a perturbative and iterative solution for strong distortion.

Conclusions:

• An educated guess for the distortion center enables iterative solutions.
• The vector-based model can be iteratively obtained from a distortion-free solution.
• Demonstrated the efficacy of the extended calibration model for endoscopic fisheye lenses.