Extrinsic Camera Calibration with Line-Laser Projection

• Main Authors: Izaak Van Crombrugge, Rudi Penne, Steve Vanlanduit
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Sensors
• Subjects: camera calibration; multi-camera; extrinsic calibration; non-overlap; field of view
• Online Access: https://www.mdpi.com/1424-8220/21/4/1091

Knowledge of precise camera poses is vital for multi-camera setups. Camera intrinsics can be obtained for each camera separately in lab conditions. For fixed multi-camera setups, the extrinsic calibration can only be done in situ. Usually, some markers are used, like checkerboards, requiring some level of overlap between cameras. In this work, we propose a method for cases with little or no overlap. Laser lines are projected on a plane (e.g., floor or wall) using a laser line projector. The pose of the plane and cameras is then optimized using bundle adjustment to match the lines seen by the cameras. To find the extrinsic calibration, only a partial overlap between the laser lines and the field of view of the cameras is needed. Real-world experiments were conducted both with and without overlapping fields of view, resulting in rotation errors below 0.5°. We show that the accuracy is comparable to other state-of-the-art methods while offering a more practical procedure. The method can also be used in large-scale applications and can be fully automated.