改进的平面模板两步法标定摄像机

Improved Two-stages Camera Calibration From a Plane

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。

Zhengyou Zhang has proposeda Two Stages camera calibration method by viewing a plane recently .It can calibrate camera easily with high accuracy and is considered as apresen tation of Two Stages method .But only radial distortion is considered in his camera model,and when the tangential distortion is distinc tin some lenses,such as in fish eye-lenses ,the camera model will beunsui table.There for his came ramodelisi mproved in thispaperandan improved Two stages method is proposed .Through the proposed method the initial parameter sare solved by using the pointsnear the imageplanecenter.Asthe distortionis very litter near the image planecenter,the solved initial parameters can bevery close to exactones ,then ,as ubspacetrustregion method based on the interior reflective New tonmethodi sapplied to solve all the cameraparametersac curately.Both computersi mulation and real data have been used to test the proposed technique and very good resultshave been obtained .Compared with Zhang’s method ,the proposed method is more accurate and it works better robustness .