Epipolar geometry for trinocular active range-sensors

of these for certain types of scene, so we hope to be able to label lines and nodes successfully without any type of coding. We investigate recent ideas in the design of irinocular active range-sensors. Such devices have the advantage of freedom from mechanical scanning, and rapid image capture. The main technical problem is overcoming the correspondence problem. This requires careful geometric design to take account of epipolar geometry and thorough modelling of image-measurement error. We present a novel design that, so far, seems to work well. Curiously it involves setting up the projectorcamera geometry to be degenerate — so that depth computation is ill-conditioned — and then backing off a little.