Increasing Camera Pose Estimation Accuracy Using Multiple Markers

If the geometry of a marker is known and camera parameters are available, it is possible to recover a camera pose. The transformation between a camera and a marker is defined relative to the local coordinate system of the marker. This paper proposes a real-time camera tracking method using multiple markers while the camera is allowed to move freely in a 3D space. We utilize multiple markers to improve the accuracy of the pose estimation. We also present a coordinate registration algorithm to obtain a global optimal camera pose from local transformations of multiple markers. For the registration, a reference marker is automatically chosen among multiple markers and the global camera pose is computed using all local transforms weighted by marker detection confidence rates. Experimental results show that the proposed method provides more accurate camera poses than those from other methods.