1. [Publications](/publications)
2. Camera Re-calibration after Zooming based on Sets of Conics
 
 # Camera Re-calibration after Zooming based on Sets of Conics

  ![](/sites/default/files/styles/wide/public/pubs/2015-05_Camera-Re-calibration-after/default.jpg?itok=b8MyER5Q)

 We describe a method to compute the internal parameters (focal and principal point) of a camera with known position and orientation, based on the observation of two or more conics on a known plane. The conics can even be degenerate (e.g., pairs of lines). The proposed method can be used to re-estimate the internal parameters of a fully calibrated camera after zooming to a new, unknown, focal length. It also allows estimating the internal parameters when a second, fully calibrated camera observes the same conics. The parameters estimated through the proposed method are coherent with the output of more traditional procedures that require a higher number of calibration images. A deep analysis of the geometrical configurations that influence the proposed method is also reported.



 ## Authors



[Iuri Frosio](/person/iuri-frosio)

Cristina Turrini (NVIDIA)

Alberto Alzati (NVIDIA)

 

 

 ## Publication Date



Friday, May 1, 2015

 

 ## Published in



[The Visual Computer](http://link.springer.com/article/10.1007%2Fs00371-015-1089-8)

 

 ## Research Area



[Computer Vision](/research-area/computer-vision)

 

 

 ## External Links



[Paper](http://link.springer.com/article/10.1007%2Fs00371-015-1089-8)