Easy Calibration of a Blind-Spot-Free Fisheye Camera System Using a Scene of a Parking Space

Mounting three fisheye cameras, on the sides and rear of a vehicle, can help a driver maneuver his/her vehicle in restricted environments by providing a top view that is generated from these three fisheye cameras. To generate the top view, the pose of each fisheye camera must first be calibrated. In this paper, we propose an easy method of calibrating such a fisheye camera system by observing the scene of a parking space. First, each camera pose relative to the ground is estimated from the typical line pattern of a parking space. Then, the relative pose among the three cameras is refined using the overlapping region of the ground between the neighboring cameras. Finally, if necessary, any small deviation of the pose of the camera system can manually be adjusted by an interactive interface. Since the calibration of the fisheye camera system can be performed without preparing a specific calibration pattern for this particular purpose beforehand, the proposed method can reduce the workload on the user. Experimental results reveal the effectiveness of the proposed method.