Uncalibrated Stereo Vision with Pointing for a Man-Machine Interface

Here we report preliminary work on a gesturebased interface for robot guidance. The system requires no physical contact with the o p erator, but uses unca l ib ra ted s te reo vision with ac t ive con tours to track the position and pointing direction of a hand. With a g r o u n d p lane cons t ra in t , it is then possible to find the indicated position in the robot's workspace, by considering only two-dimensional collineations. The system is accurate to about 2cm in a 40cm workspace; natural operator feedback improves this to within Icm. It is initialised by observing just 4 points on the plane.