大视场光电测量系统广角相机标定方法研究  

Research on calibration method of wide-angle camera for large field of view photoelectric measurement system

作　　者：刘泉新 林世治[1] 吴光强 陈丹 吴坤华[1] 陈生[1] 张亚 LIU Quanxin;LIN Shizhi;WU Guangqiang;CHEN Dan;WU Kunhua;CHENG Sheng;ZHANG Ya(Department of Electrical Engineering,Fujan College of Water Conservancy and Electric Power,Yongan 366000,China)

机构地区：[1]福建水利电力职业技术学院电力工程系,福建永安366000

出　　处：《光学技术》2022年第4期452-458,共7页Optical Technique

基　　金：福建省中青年教师教育科研项目(JAT201143);福建水院高层次人才科研启动项目(gccrcyjxm_lqx);福建水院基金重点项目A级(YJKJ2102A)。

摘　　要：在大视场光电测量系统中一般会采用广角镜头,这会导致获得的测量图像存在严重的畸变问题。为了对这一类大畸变相机进行精确标定,可以通过径向畸变除式模型以及角点亚像素坐标提取方法,首先求解出图像畸变中心坐标及畸变参数,然后利用二维平面棋盘格标志点与图像点的对应关系求解出单应性矩阵,再根据单应性矩阵进一步求解出相机内外参数。求解出相关参数后,对求解出的参数利用Levenberg-Marquardt法进行迭代优化,再在迭代优化的基础上根据3σ法则对重投影误差数据进行坏点剔除,然后对剔除坏点之后的坐标数据重新进行标定,直至所有数据都符合要求,最终可以实现大视场畸变图像的高精度校正。为了验证所提方法的有效性,进行了仿真图像及实际图像的标定实验,结果显示,本方法能适当提高标定精度,在实际实验中均方重投影误差平均值减小了0.0103个像素点,相当于提升了0.7%的校正误差精度。Wide-angle lenses are generally used in photoelectric measurement systems with large fields of view, which will cause serious distortion problems in the obtained measurement images. In order to accurately calibrate this type of large-distortion camera, the radial distortion division model and the corner sub-pixel coordinate extraction method are used to first solve the image distortion center coordinates and distortion parameters. and then uses the two-dimensional plane checkerboard marker points and The corresponding relationship of the image points is used to solve the homography matrix, and then the internal and external parameters of the camera are further solved according to the homography matrix. After solving the relevant parameters, use the Levenberg-Marquardt method to iteratively optimize the solved parameters, and then based on the iterative optimization, the reprojection error data is eliminated according to the 3σ rule. Calibration is performed until all data meet the requirements, and finally high-precision correction of large-field-of-view distorted images can be achieved. In order to verify the effectiveness of the proposed method, calibration experiments on simulated images and actual images are carried out. The results show that this method can appropriately improve the calibration accuracy. In the actual experiment, the average mean square reprojection error is reduced by 0.0103 pixels, which is equivalent to improving the correction error accuracy by 0.7%.

关 键 词：光电测量 相机标定 迭代优化 坏点剔除 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]