一种基于圆形标志点的摄像机标定方法

AN CAMERA CALIBRATION METHOD BASE ON CIRCULAR FEATURE POINTS

摄像机标定是估计成像过程中的摄像机参数,它直接影响测量的准确性。本文针对圆形标定板的特性,提出了一种基于圆形标志点的摄像机标定方法。首先,提取图像中目标轮廓,用区域属性函数获得图像中目标的属性,计算出标志圆质心的坐标;然后用Zhang提出的基于平面两步标定法进行摄像机标定,并对内参数运用最大似然估计求解;外参数运用最小二乘法和最大似然估计算法求解;最后,对标定结果进行评价。实验结果表明,标定残差的平均误差在0.3以下,验证标定方法的可行与有效性。

Camera calibration is the estimation of parameters associated with a camera being used for imaging, which directly affects the accuracy of the measurement. According to the characteristic of circular board, a camera calibration based on the circular feature points was presented. First, extracting the target outlines and obtaining the target properties used to the function can calculate the coor- dinates of calibration circle. Than, calibration camera adopted the plane calibration method put forward by Zhang. The intrinsic param- eters were estimated by means of levenberg - marquardt and the extrinsic parameters were computed by applying to the least square method and levenberg - marquardt. Experimental results show that the mean error of calibration residual is less than 0.3 pixels. So the calibration method is feasible and effective.