Camera Pan-Tilt Ego-Motion Tracking from Point-Based Environment Models

We propose a point-based environment model (PEM) to represent the absolute coordinate frame in which camera motion is to be tracked. The PEM can easily be acquired by laser scanning both indoors and outdoors even over long distances. The approach avoids any expensive modeling step and instead uses the raw point data for scene representation. Also the approach requires no additional artificial markers or active components as orientation cues. Using intensity feature detection techniques key points are automatically extracted from the PEM and tracked across the image sequence. The orientation procedure of the imaging sensor is solely based on spatial resection.