TY - JOUR
T1 - Development of a camera model and calibration procedure for oblique-viewing endoscopes
AU - Yamaguchi, Tetsuzo
AU - Nakamoto, Masahiko
AU - Sato, Yoshinobu
AU - Konishi, Kozo
AU - Hashizume, Makoto
AU - Sugano, Nobuhiko
AU - Yoshikawa, Hideki
AU - Tamura, Shinichi
N1 - Funding Information:
This work was partly supported by JSPS Research for the Future Program JSPS-RFTF99I00903.
PY - 2004
Y1 - 2004
N2 - Oblique-viewing endoscopes (oblique scopes) are widely used in medical practice. They are essential for certain procedures such as laparoscopy, arthroscopy and sinus endoscopy. In an oblique scope the viewing directions are changeable by rotating the scope cylinder. Although a camera calibration method is necessary to apply augmented reality technologies to oblique endoscopic procedures, no method for oblique scope calibration has yet been developed. In the present paper, we formulate a camera model and a calibration procedure for oblique scopes. In the calibration procedure, Tsai's calibration is performed at zero rotation of the scope cylinder, then the variation of the external camera parameters corresponding to the rotation of the scope cylinder is modeled and estimated as a function of the rotation angle. Accurate estimation of the rotational axis is included in the procedure. The accuracy of this estimation was demonstrated to have a significant effect on overall calibration accuracy in the experimental evaluation, especially with large rotation angles. The projection error in the image plane was approximately two pixels. The proposed method was shown to be clinically applicable.
AB - Oblique-viewing endoscopes (oblique scopes) are widely used in medical practice. They are essential for certain procedures such as laparoscopy, arthroscopy and sinus endoscopy. In an oblique scope the viewing directions are changeable by rotating the scope cylinder. Although a camera calibration method is necessary to apply augmented reality technologies to oblique endoscopic procedures, no method for oblique scope calibration has yet been developed. In the present paper, we formulate a camera model and a calibration procedure for oblique scopes. In the calibration procedure, Tsai's calibration is performed at zero rotation of the scope cylinder, then the variation of the external camera parameters corresponding to the rotation of the scope cylinder is modeled and estimated as a function of the rotation angle. Accurate estimation of the rotational axis is included in the procedure. The accuracy of this estimation was demonstrated to have a significant effect on overall calibration accuracy in the experimental evaluation, especially with large rotation angles. The projection error in the image plane was approximately two pixels. The proposed method was shown to be clinically applicable.
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U2 - 10.1080/10929080500163505
DO - 10.1080/10929080500163505
M3 - Article
C2 - 16192062
AN - SCOPUS:23644439753
SN - 1092-9088
VL - 9
SP - 203
EP - 214
JO - Computer Aided Surgery
JF - Computer Aided Surgery
IS - 5
ER -