Acquisition of spherical image by fish-eye conversion lens

In this paper, we propose a novel method of calibrating a spherical image capture system which acquires spherical images by using a pair of fish-eye conversion lenses with the field of view more than hemisphere, respectively. We first exploit the vanishing points for estimating internal parameters of a camera with the fish-eye conversion lens and the relative orientation between the both of fish-eye cameras. Then, these parameters are refined by computing the correlation of the overlapping parts of the two images.