How accurate can a stereovision measurement be?

What is the best accuracy that can be achieved with two cameras in a stereovision arrangement? Stereovision allows 3D measurement. Such arrangements are used more and more and can be a cost effective way of taking complex measurements. However, it turns out that the complex relationship between the parameters on which the result depends makes it difficult to judge the accuracy that can be achieved. This paper reviews some of the literature on stereovision accuracy using CCD cameras. It then derives a limit for the accuracy based on the current state of the art technology. The limit is analytically derived from the pin hole camera model and incorporates both the intrinsic and extrinsic camera parameters as well as the quantization error. Finally, the paper explores the influence of the uncertainty of all the camera parameters as well and the quantization uncertainty. The accuracy model derived in the paper will be useful for practitioners wishing to determine the best achievable accuracy of a particular stereo camera arrangement.