Detecting the ground using an omnidirectional stereo vision system.

http://www.youtube.com/watch?v=JhNotSaBmnA

The green features in the centre mirror have been identified as being close to the ground plane.

Edge features close to the ground plane are detected by projecting all features from the centre mirror to the ground plane (the height of the camera is known), then reprojecting the ground features back into the image plane of the four peripheral mirrors. The reverse operation is then applied, and features within the centre mirror are compared. Features with small reprojection error must belong somewhere close to the ground plane.

This provides a convenient and general way of locating the ground, which does not depend upon unreliable texture, colour histogram or image segmentation methods.