Pose estimation for free binocular cameras based on reprojection error optimization
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摘要: 在自由双目立体视觉系统中,左右相机自由旋转,导致相机位姿发生实时变化。针对这一问题,提出一种重投影优化的自由双目相机位姿估计方法。通过分解相邻两幅图像间的单应矩阵估计相机的运动参数;将其作为初值计算重叠拍摄区域内特征点云的重投影误差,构建目标函数;利用非线性优化算法优化目标函数,得到最优的相机运动参数,结合相机旋转前的位姿参数,计算当前位置的相机位姿。仿真实验表明,位姿估计误差随重投影误差的减小而减小,所提算法能快速稳定收敛至全局最优值;水泥模型的三维重建实验表明,利用所提的相机位姿估计算法能够有效生成模型的三维点云,并可实现相邻点云的高精度拼接,拼接点云模型上两点距离的平均误差为1.68%。Abstract: To solve the real-time change of the camera poses caused by the rotation of cameras in free binocular stereo vision, a method for estimating the poses of free binocular cameras based on reprojection error optimization is proposed. The movement paraments of cameras are estimated by decomposing the homography matrix between two adjacent images. Then, the reprojection error of feature points in the overlapping area is calculated, and the objective function is constructed by using the movement parameters as initial values. Finally, the objective function is optimized by the nonlinear optimization algorithm, and the current camera poses are calculated by combining with the optimal movement parameters and the camera poses before rotation. Simulations indicate that the pose estimation error declines with a decrease in reprojection error and the proposed method can converge to a globally optimal solution both rapidly and stably. An experiment of 3D reconstruction of cement models indicates that 3D point clouds of models are generated effectively with the proposed method, the adjacent point clouds are stitched accurately, and the average error of distance between any two points on the stitched point clouds is 1.68%.
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Key words:
- pose estimation /
- stereo vision /
- reprojection error /
- nonlinear optimization /
- 3D reconstruction
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表 1 标志点间距
Table 1. Distance between mark points
(mm) 实验次数 AB间距 CD间距 EF间距 1 498.073 199.762 501.328 2 501.137 197.037 501.670 3 500.569 198.053 502.404 4 502.842 200.459 502.634 -
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