Fig. 1. Schematic diagram of 30° laparoscope

Fig. 2. Relative percent distortion curve of endoscope

Fig. 3. Pattern of calibration target plate

Fig. 4. Schematic diagram of calibration

Fig. 5. Distortion of target plate

Fig. 6. Schematic diagram of overall system design

Fig. 7. Flow chart of system work

Fig. 8. Physical image of overall testing device

Fig. 9. Diagram of software interface

Fig. 10. Coincidence images of calibration target plate

Fig. 11. Calibrated relative percent distortion measurement image

Fig. 12. Relative percent distortion detection images without vertical calibration