Accuracy of 3D motion tracking using a stereocamera

Several approaches for tracking the movement of objects in 3D space exist. Most of them actually track the motion of special sensors attached to the object of interest. This method is often not appropriate, because it obstructs the free movement of the object. However, some localization approaches depend only on natural properties of objects and don´t require any special hardware. In this paper we present the overview of an optical tracking system that uses stereoscopic camera to detect motion. To estimate its accuracy we compare the results with reference measurements made by magnetic tracking device. We report results of several experiments and present the main factors that contribute to the total tracking error. The average difference between the two tracking systems is 1.7 cm. In the end we present a few improvements that could further reduce the tracking error.