Stabilizing Marker-Based Visual Tracking Using Markers with Scattering Materials and Multiple Cameras

The marker-based method in visual tracking is generally convenient, while the stability of the position and orientation estimation of the camera depends on the illumination conditions because it is processed on the basis of the camera images. However, illumination conditions are often difficult to control in practical environments. Although some solutions have been proposed for illumination changes, the methods based on image processing have unstable estimation due to specular reflection on markers. Thus, effects on illumination were avoided by using markers with scattering materials. In addition, multiple cameras were also used for stabilizing the orientation estimation when the optical axis of the camera is almost perpendicular to the marker surface.