A practical spherical mirror omnidirectional camera

Abstract

A practical omnidirectional camera consisting of one spherical mirror, a mirror supporting structure and a mega pixel digital imaging system has been developed. The camera can view a field of 360 degrees horizontally and 135 degrees vertically. We have analyzed the image forming and depth of field characteristics of the spherical mirror and, for comparison, a hyperboloidal mirror. Advantages of the spherical mirror are its large field of view, good focus over the entire field, simple construction, and low manufacturing cost. Demerits of the mirrors are also evaluated, and practical limitations are described. We have also developed image processing software in which a circular image is converted to desired images in real time. Several prototype cameras have been developed