An Extended Marker-Based Tracking System for Augmented Reality

Fiducial marker systems consist of unique patterns mounted in the environment and computer vision algorithms that help automatically find features in digital camera images. They are useful for Augmented Reality (AR), robot navigation, 3D modeling, and other applications. In this paper we introduce an extension of marker-based approaches. For some applications which need a large working space, we mounted markers onto the ceiling. Two cameras are fixed onto the head-mounted displays (one captures the markers and the other captures the real scene). After calibration of the two cameras, the pose of the camera captures the real scene can be obtained to merge virtual scene.