An interactive method for extrinsic parameter calibration of onboard camera

In vision-based driver assistance applications, the onboard cameras are supposed to be calibrated as simply and accurately as possible. This paper presents an interactive method for extrinsic parameter calibration of onboard camera. In the proposed method, the intrinsic camera parameters are assumed to be known. During the calibration process, we first design a calibration scene to compute the extrinsic camera parameters. There are three lines in the scene, two of which are parallel with the vehicle heading direction and the other one is perpendicular with the first two. Then, using this scene, we derive an interactive and analytical solution to obtain the extrinsic camera parameters, which can adequately compromise the calibration complexity and accuracy. We also extend the method to multiple cameras, in which case the calibration can be performed without absolute positions of the calibration lines. Theoretical and experimental results show the efficiency of the proposed calibration method.