双目立体测量系统标定及精度评价

CALIBRATION AND ACCURACY EVALUATION OF BINOCULAR STEREO MEASUREMENT SYSTEM

摄像机标定是双目立体测量系统的基础,标定精度也最终影响着整个系统的测量精度。Zhang提出的平面模板标定法通过采用一种具有特征点的平面靶标来进行标定,操作简便,精度高。关于此方法,不同类型的靶标具有的特征点提取精度也不同,从而影响着摄像机标定精度。采用棋盘和圆点阵列两种类型靶标分别进行摄像机标定,然后利用标定结果进行三维测量,以三维测量精度作为标定精度评价依据。实验表明,相较于棋盘靶标,采用圆点阵列靶标进行摄像机标定,将会获得更高的标定精度。

Camera calibration is the foundation of binocular stereo measurement system, and the calibration precision also affects the measuring precision of whole system eventually. The plane template calibration method proposed by Zbang calibrates by using a plane target with feature points, and it is easy in operation and high in accuracy. For this method, it has different precisions on feature point extraction for different targets, therefore the camera calibration preeisions are impacted. In this paper we propose to use two kinds of targets, the checker target and circle array target, to carry out the camera calibration respectively, and then using the calibrated results for 3-dimensional measurement, and taking the 3D measuring precision as the basis of the calibration precision evaluation. Experiment demonstrates that compared with checker target, the camera calibration will obtain higher calibration precision by using circle array target.