Circular markers for camera pose estimation

Circular markers for camera pose estimation
Alain Pagani, Johannes Köhler, Didier Stricker
Proceedings of the 12th International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS 2011) International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS-2011), 12th, April 13-15, Delft, Netherlands

Abstract:

This paper presents a new system using circular markers to estimate the pose of a camera. Contrary to most markers-based systems using square markers, we advocate the use of circular markers, as we believe that they are easier to detect and provide a pose estimate that is more robust to noise. Unlike existing systems using circular markers, our method computes the exact pose from one single circular marker, and do not need specific points being explicitly shown on the marker (like center, or axes orientation). Indeed, the center and orientation is encoded directly in the marker's code. We can thus use the entire marker surface for the code design. After solving the back projection problem for one conic correspondence, we end up with two possible poses. We show how to find the marker's code, rotation and final pose in one single step, by using a pyramidal cross-correlation optimizer. The marker tracker runs at 100 frames/second on a desktop PC and 30 frames/second on a hand-held UMPC.