A full geometric and photometric calibration method for oblique-viewing endoscopes

Area of Science:

• Medical Imaging
• Computer Vision
• Surgical Technology

Background:

• Oblique-viewing endoscopes (oblique scopes) are essential in computer-assisted surgeries, offering an extended field of view.
• Rotating the scope cylinder changes the viewing direction but complicates geometric calibration.
• Photometric calibration is vital for illumination-based visualization but has not been addressed for endoscopes.

Purpose of the Study:

• To present a comprehensive calibration process for oblique-viewing endoscopes.
• To estimate both the geometric and photometric properties of oblique scopes.
• To enable advanced augmented reality and visualization techniques in surgery.

Main Methods:

• Developed a novel geometric calibration technique for oblique scopes.
• Introduced the first photometric calibration method specifically for endoscopes.
• Integrated both geometric and photometric calibration into a complete process.

Main Results:

• The proposed methods provide accurate estimation of geometric parameters.
• The photometric calibration effectively addresses illumination variations.
• Experimental validation confirms the practicality and accuracy of the complete calibration process.

Conclusions:

• The presented complete calibration process is practical and accurate for oblique-viewing endoscopes.
• This work enables more reliable augmented reality and illumination-based visualization in surgery.
• Further research can build upon these methods for enhanced surgical guidance.