采用非参模型的线阵CCD内参校准方法

Internal Calibration Method of Linear Array CCD Using Nonparametric Model

现有线阵CCD内参校准方法往往依赖于畸变参数模型,其标定精度受限于模型内部参数的相关性,因此为提高线阵CCD相机内参校准精度,提出一种采用非参数模型的线阵CCD相机内参校准方法。通过小孔成像模型和垂线法,构建线阵CCD相机成像的非参数模型,直接确定空间特征点与成像点间的映射关系以及理想成像点与实际成像点间的畸变量大小。采用重投影误差作为评价标准,与采用参数模型的内参校准方法作对比实验,实验结果表明,由所提方法得到的重投影误差的均方根、平均值和最大值分别为0.42,0.00,0.95pixel,均小于由基于参数模型的内参校准方法得到的0.80,-0.10,2.47pixel。

The existing internal calibration methods of a linear array CCD camera generally depend on the distortion parametric model,and the calibration accuracy is limited by the correlation of internal parameters of the model.Herein,an internal calibration method of linear array CCD camera using a nonparametric model is proposed to improve the internal calibration accuracy.Through the pinhole imaging model and the perpendicular method,a nonparametric model of linear array CCD camera imaging is constructed,and the mapping relationship between spatial feature points and imaging points and the size of the distortion between the ideal imaging point and the actual imaging point are directly determined.The reprojection error is used as the evaluation standard to compare the proposed method with the internal calibration method using the parametric model.The experimental results show that the root mean square,average value,and maximum value of the reprojection errors obtained using the proposed method are 0.42,0.00,and 0.95pixel,respectively,which are 0.80,-0.10,and 2.47pixel less than that obtained using the internal calibration method using the parametric model.