Omnidirectional Vision
In recent years, cameras with a large field of view, often referred to as Omnidirectional Cameras, quickly gained popularity in robotics. Expansive sources of information, as provided by wide angle visual sensors, and omnidirectional sensors facilititate visual motion detection mechanisms as observed in some biological prototypes like insects. Typically Catadioptric Omnidirectional Cameras, which are a combination of a standard camera with a lens pointing towards a curved mirror, are used. This setup provides a horizontal 360 view. The larger field of view comes at the cost of lower resolution in the outermost image regions. The geometrical properties and the distortion introduced by the re ection of the mirror are dependent on its shape and should thus be designed carefully. The mirror geometry can be shaped such that it approximates a perspective projection or a spherical projection. It is also possible to design mirrors that eliminate some reflectional distortions.