The cata-fisheye camera is a panoramic imaging system which uses a curved mirror as a simple optical attachment to a fisheye
lens. The cata-fisheye camera
has a simple, compact and inexpensive design, and at the same time yields high optical performance. It
is most suitable for capturing panoramic images with a reasonable vertical field of view
that has more or less equal coverage above and beneath the horizon - ideal for applications like perimeter
surveillance, video conferencing and navigation. The camera captures
the desired panoramic field of view in two parts -- the upper part is obtained directly by the fisheye
lens, and the lower part after reflection by the curved mirror. These two parts of the field of view
have a small overlap that is used to stitch them into a single seamless panorama.
concept allows the design of cameras with a wide range of fields of view by simply varying the parameters
and position of the curved mirror. We provide a framework for designing cata-fisheye
cameras where, for a given required panoramic field of view, the framework computes the optimal mirror parameters.
We also provide a simple automatic method for the one-time calibration needed to stitch the two parts
of the panoramic field of view. Finally, we have evaluated our design with respect to the optical quality of
the captured images, the working range of the
camera over which the parallax is negligible, and the spatial resolution of the computed panorama.
Our prototype cata-fisheye video camera is designed using a spherical mirror and can capture high
resolution panoramic images (3600x550 pixels) with a 360 degree (horizontal) x 55 degree (vertical) field of view.