自动精确提取圆形标志点中心的相机标定研究  

Research on camera calibration for automatic and accurate extraction of circular marker center

作　　者：杨浩宇 张尚盈 肖莉[1] 高翔[1] Yang Haoyu;Zhang Shangying;Xiao Li;Gao Xiang(School of Mechanical and Electrical Engineering,Wuhan Institute of Technology,Wuhan 430205,China;Wuhan Yuqiong Technology Co.,Ltd.,Wuhan 430205,China)

机构地区：[1]武汉工程大学机电工程学院,武汉430205 [2]武汉誉琼科技有限公司,武汉430205

出　　处：《电子测量技术》2021年第19期155-160,共6页Electronic Measurement Technology

基　　金：国家自然科学基金(51875415)项目资助。

摘　　要：为了提高标定精度,提出一种自动精确提取圆形标志点中心的方法,并进行相机标定的研究。首先将标定图像进行预处理,接着通过程序算法自动提取标定板上的4个圆形标志点中心来进行图像校正,其次应用一种自动迭代投影的方法,对校正图像进行迭代处理,最后再经过反透视投影得到原始标定图像的标志点中心坐标。设计了手动和自动两种提取方式,将最后提取的标志点中心坐标代入张正友标定算法中,并考虑切向畸变,求得相机的标定参数。实验结果表明,随着迭代次数的增加,重投影误差越来越大,当迭代次数为1次时,标定的精度好于多次迭代的精度,并且略高于手动提取的精度。对比维视商业软件的标定标准0.2 pixel,精度提高了58%左右。In order to improve the calibration accuracy,a method of automatically and accurately extracting the center of the circular marker point is proposed by the paper,and the research of camera calibration is carried out.Firstly,the calibration image is preprocessed,and then the center of four circular markers on the calibration board are automatically extracted by the program to perform image correction.Secondly,an automatic iterative projection method is applied to iteratively process the corrected image,and finally the center coordinates of the mark point on the original calibration image are obtained through anti-perspective projection.Two extraction methods including manual and automatic are designed.The center coordinates of the last extracted mark points are substituted into Zhang Zhengyou′s calibration algorithm,and the tangential distortion is considered to obtain the calibration parameters of the camera.The experimental results show that as the number of iterations increases,the reprojection error becomes larger and larger.When the number of iterations is one,the accuracy of calibration is better than that of multiple iterations,and it is slightly higher than the accuracy of manual extraction.Compared with the 0.2 pixel calibration standard of Microvision commercial software,the accuracy has been improved by about 58%.

关 键 词：圆形标志点中心 自动提取 图像校正 自动迭代投影 重投影误差 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]