![](bg8.png)
Figure 9: (a) The rectified result through the image of blue
cup, (b) The rectified result through the image of red cup.
that the focal length can be calibrated from one circle
image. Firstly, we derive the necessary and sufficient
conditionsof paracatadioptric circle image. Secondly,
these conditions are used to limit the search space to
accurately estimate circle image. What’s more, we
show that the focal length can be computed from the
estimated circle image and the principal point that
is estimated from the projected contour of parabolic
mirror. Both the simulated and real data experiments
validate the effectiveness of our method. In our future
work, we continue to study the calibration method of
central catadioptric camera from circle images.
ACKNOWLEDGEMENTS
This work was supported by National Sci-
ence and Technology Support Projects of China
(No.2012BAH07B01).
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