System for Robust Bronchoscopic Video DistortionCorrection

摘要

Bronchoscopes contain wide-angle lenses that produce a large field of view but suffer from radial distortion. For image-guided bronchoscopy, geometric calibration including distortion correction is essential for comparing video images to renderings developed from 3D computed-tomography (CT) images. This paper describes an easy-to-use system for bronchoscopic video-distortion correction and studies the robustness of the resulting calibration over a wide range of conditions. The internal calibration method integrated into the system incorporates a well-known camera calibration framework devised for general camera-distortion correction. The robustness study considers the calibration results as follows: (1) varying lighting during video capture, (2) using different number of captured images for parameter estimation, (3) changing camera pose with respect to the calibration pattern, (4) recording temporal changes in estimated parameters, and (5) comparing parameters between different bronchoscopes of a same model. Multiple bronchoscopes were successfully calibrated under a variety of conditions.