Zhao Chengli, Fan Chenyang, Zhao Zhangyan
School of Transportation and Logistics Engineering, Wuhan University of Technology, Wuhan, 430063, China.
CCCC Second Harbor Engineering Company LTD, Wuhan, 430040, China.
Heliyon. 2024 Sep 27;10(19):e38347. doi: 10.1016/j.heliyon.2024.e38347. eCollection 2024 Oct 15.
Camera calibration is a crucial step in binocular measurement, and the accuracy of camera calibration largely determines the measurement accuracy of binocular vision. However, the calibration accuracy of existing calibration methods is difficult to satisfy the requirements of variable calibration environments and engineering applications. Therefore, based on the principle of Zhang's calibration method, a calibration method is proposed by combining bundle adjustment and diagonal constraints of the calibration target. Firstly, the improved Canny edge extraction algorithm is used to obtain the sub-pixel center of mass of ellipse (CME). Then, the Zhang's calibration method is used to obtain the initial values of the calibration parameters. The camera calibration parameters are optimized by using the bundle adjustment. Finally, diagonal constraints are used to further optimize the extrinsic camera position parameters. The experimental results show that compared to the other excellent methods, the proposed method can significantly improve calibration accuracy and has certain engineering application value.
相机标定是双目测量中的关键步骤，相机标定的精度在很大程度上决定了双目视觉的测量精度。然而，现有标定方法的标定精度难以满足变化的标定环境和工程应用的要求。因此，基于张氏标定方法的原理，提出了一种结合光束法平差和标定靶对角约束的标定方法。首先，使用改进的Canny边缘提取算法获取椭圆质心（CME）的亚像素中心。然后，采用张氏标定方法获取标定参数的初始值。利用光束法平差对标定参数进行优化。最后，使用对角约束进一步优化相机外部位置参数。实验结果表明，与其他优秀方法相比，该方法能够显著提高标定精度，具有一定的工程应用价值。
