光栅投影式三维摄影测量仪的几何标定方法

光栅投影式三维摄影测量仪利用了时域结构光投影技术和立体视觉测量原理获得三维点坐标。针对传统标定方法易受镜头畸变影响和标定约束方程少导致精度下降的问题,采用了非线性的摄像机和投影机模型,并提出了二维的投影机模型;使用多平面法标定了系统测量所需的摄像机和投影机几何参数;为进一步提高参数精度,采用Levenberg-Marquardt算法优化了摄像机和投影机模型。实验结果表明,该方法操作简单,无需精确的位置和姿态调整,标定的绝对精度为0.2pixel,相对精度为1/5000。

Geometric calibration method of 3D photogrammetric instruments using grating projection

3D coordinates for the 3D photogrammetric instruments were acquired with temporal structure light projection technology and stereo-vision measuring algorithm. In view of the problem that the traditional methods were influenced by lens distortion and accuracy decline caused by lack of calibration restriction, the nonlinear camera and projector model was introduced and the 2D projector calibration model was proposed. Camera and projector geometrical parameters were calibrated with multi-plane method. Furthermore, the nonlinear camera and projector model was optimized by Levenberg-Marquardt algorithm to improve the precision of parameters. Operations of method are simple and there is no need to accurately adjust place and pose. Experimental results show that the accuracy of calibration can reach 0.2 pixel, and relative accuracy 1/5000.