Use of vision systems in media in which the wave speed propagation is not that one of air is a subject seldom treated in the Vision community. However, any trial to localize or reconstruct an object observed by an underwater camera (for instance) has to go through a calibration phase .
These html pages briefly presents some optical considerations relating to underwater cameras.
We show the relationship between the current pin-hole model of the camera and the general optical model of the lens combination for the same camera in air and under water. It is proved that the calibration of a camera working under water does not have to be carried out under water.
The intrinsic parameters of a camera immersed in any fluid can be computed from an air-calibration as soon as the optical surface between the two fluids presents some simple geometrical properties.
This work has been done in collaboration with the french company POSEIDON
http://www.poseidon.fr.