基于自由镜面反射位姿评估的条纹反射摄影测量

在条纹反射摄影测量中,由于产生条纹图形的液晶显示器不直接出现在摄像机的视场范围内,摄像机与液晶显示器之间的位姿标定是条纹反射摄影测量的主要难点。为了简化标定过程,提出了采用平面镜直接对液晶显示器上的条纹反射3次并利用固定摄像机接收反射条纹,通过对摄像机与条纹虚像之间的3次位姿评估,完成摄像机与液晶显示器的位姿标定的方法。在镜面面形测量中,利用两者之间的位姿关系可以将待测点的反射光线和入射光线统一在摄像机坐标系下,完成光线的三角交会,实现镜面面形测量。数值模拟和实验结果表明,此方法简单易行,且精度较高。

Fringe Reflection Photogrammetry Based on Pose Estimation with Free Planar Mirror Reflection

Since liquid crystal display (LCD) screen locates outside of the camera′s field of view in fringe reflection photogrammetry, fringe is obtained through specular reflection by a fixed camera. Thus, the pose calibration between camera and LCD screen is the main challenge in fringe reflection photogrammetry. A markerless planar mirror is used to reflect the LCD screen 3 times, and the fringe is mapped into camera. The geometrical calibration can be accomplished by estimating the pose between the camera and virtual image of fringe. With the help of the relation beween their pose, incidence and reflection ray can be unified in the camera frame, triangulation can be operated in the camera frame to measure 3D shape of specular. Results of simulations and experiments demonstrate that the approach is simple, feasible and has high accuracy.