Real-Time Control of Active Stereo Vision System

This paper describes an approach for tracking objects in 3D scene using Stereo Vision System with the control of cameras gaze and vergence. The goal of camera positioning mechanism is to keep cameras fixed on a common visual target. Mechanical linkage between cameras ensures separate control of vergence and gaze angles and the same distance from the left and the right camera to the fixated world point. Keeping the tracking target fixated causes that object lies near horopter - a surface with zero disparity. It means that stereo images of this object have a narrow range of disparities and makes it possible to use stereo algorithm that accepts only a limited range of disparities. On the other hand, most of the stereo matching algorithms need fully rectified input images or at least accurate camera calibration parameters. Side effect of such active control of cameras positioning is a continuous degradation of calibration and needs re-calibration or estimation of stereo parameters for each new position.