Pose estimation for free binocular cameras based on reprojection error optimization

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%.