Image-enhanced endoscopy calibration and image registration accuracy testing

Combining endoscopic video with overlaid reconstructed 3D images allows surgeons to see past opaque surfaces and provides 2D and 3D planning and navigation information. Ensuring surgical quality necessitates accurate calibration and accuracy testing of such systems, as errors from sources such as uncompensated lens distortion and the tracking system cause image misregistration. A method for the calibration of an image-enhanced endoscopy system is presented. Constant-radius linear compensation is proposed as an alternative to computationally expensive nonlinear radial lens-distortion compensation. The results of a system accuracy test using these methods are discussed and the linear lens-distortion compensation method is shown to be an effective compromise between computational speed and accuracy.