改进的平面模板两步法标定摄像机.docVIP

中国图象图形学报Journal of Image and Graphics第 中国图象图形学报 Journal of Image and Graphics 第 9 卷 第 7 期 2004 年 7 月 Vol . 9 ,No . 7 J uly 2004 改进的平面模板两步法标定摄像机 1) ,2) 1) 1) 毛剑飞 邹细勇 诸 静 1) ( 浙江大学电气自动化研究所 ,杭州 310027) 2) ( 浙江大学工业控制技术国家重点实验室 ,杭州 310027) 摘 要 最近 ,张正友提出用平面模板两步法来标定摄像机 。该方法能高精度地标定摄像机 ,且简便易行 ,可以说 是两步法标定的代表 ,但其算法模型仅考虑了镜头径向畸变 ,其对切向畸变较大的场合 ,如鱼眼镜头成像 ,则不适 用 。为此 ,通过改进其摄像机模型 ,提出了一种改进的两步法 ,该方法先用图像中心附近点求取初值 ,由于图像中 心附近点畸变很小 ,故求取的初值能很好地逼近准确值 ,然后采用一种基于内部映射牛顿法的子空间置信域法通 过求精来得到所有参数 。仿真实验和真实实验的结果表明 ,该方法的标定精度要优于张正友的方法 ,鲁棒性也更 好 。 关键词 摄像机标定 平面模板两步法 切向畸变 图像中心附近点 子空间置信域法 中图法分类号 : TP242. 62 TN948. 41 文献标识码 : A 文章编号 : 100628961 (2004) 0720846207 Improved Two2stages Ca mera Calibration From a Plane MAO J ian2fei1) ,2) , ZOU Xi2yong1) , ZHU J ing1) 1) ( Institute of Electrical Automation , Zhejiang University , Hangzhou 310027) 2) ( National L aboratory of Industrial Control Technology , Zhejiang University , Hangzhou 310027) Abctract Zhengyou Zhang has proposed a Two2Stages camera calibration method by viewing a plane recently. It can calibrate camera easily with high accuracy and is considered as a presentation of Two2Stages method. But only radial distortion is considered in his camera model , and when the tangential distortion is distinct in some lenses , such as in fish2eye lenses , the camera model will be unsuitable . Therefor his camera model is improved in this paper and an improved Two2stages method is proposed. Through the proposed method the initial parameters are solved by using the points near the image plane center. As the distortion is very li2t ter near the image plane center , the solved initial parameters can be very close to exact ones , then , a subspace trust region method based on the interior2reflective Newton method is applied to solve all the camera parameters accurately. Both computer simulation and real data have been used to test the proposed technique and very good results have been obtained. Compared with Zhang’s method , the