针对野外复杂地形环境下,对于多个监测区域进行野外坐标测量的情况,提出一种利用双目立体视觉原理对相机3个姿态角及焦距同时进行现场校准的快速标定方法.该方法对传统的标定方法进行改进,可用于相机焦距、姿态未知的情况,对现场环境条件要求低,避免了传统标定方法中相机架设姿态受限的问题.首先通过选择合适的统一世界坐标系和坐标系旋转顺序,使标定得到的相机外参与相机姿态角对应.然后通过GPS测量得到两个标定点的世界坐标,将两个标定点的世界坐标和图像坐标代入成像模型,用最小二乘法解出相机的焦距和姿态角.在现场对其中一个监测区域进行实际测量验证,结果显示直径200 m的圆形监测区域内,相对误差优于0.38%.该方法工程应用性强,灵活度高,适用性广.%In view of the complex terrain and the field coordinate measurements in multiple monitoring areas,a rapid calibration method based on the principle of binocular stereo vision for simultaneous cal-ibration of three camera attitude angles and focal length was proposed.This method improved the tra-ditional calibration method,so that it could be used for the situation that the camera focus and atti-tudes were all unknown,and had low requirement for field environment conditions.It avoided the problem of camera pose limitation in traditional calibration method.First,selected the unified world coordinate system and right coordinate rotation order,so that the calibration parameter equaled the corresponding camera attitude angles.Then,put the pixel coordinates and the world coordinates of two given points into camera imaging model,and the focal length and three attitude angles of the cam-era was solved by the least square method.The actual measurement and verification of one of the tar-get areas were carried out on the spot.The results show that the relative error in the circular monito-ring area of diameter 200 m is better than 0.38%.The method proposed is of high engineering appli-cability,and high flexibility and wide applicability.
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