A novel dual-camera calibration method for 3D optical measurement. (May 2018)

• Record Type: Journal Article
• Authors: Gai, Shaoyan; Da, Feipeng; Dai, Xianqiang
• Is Part Of: Optics and lasers in engineering. Volume 104(2018)
• Page Start: 126
• Page End: 134
• Publication Date: 2018-05
• Subjects: 3D measurement -- Calibration -- Binocular vision optics -- Reconstruction error; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2017.09.025
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: The objective function directly indicates the efficiency of 3D reconstruction. The accuracy is improved significantly by the proposed method. The degree of coupling between parameters is reduced during calibration. The proposed method is convenient. There is no strict requirement on position of calibration plate. Abstract: A novel dual-camera calibration method is presented. In the classic methods, the camera parameters are usually calculated and optimized by the reprojection error. However, for a system designed for 3D optical measurement, this error does not denote the result of 3D reconstruction. In the presented method, a planar calibration plate is used. In the beginning, images of calibration plate are snapped from several orientations in the measurement range. The initial parameters of the two cameras are obtained by the images. Then, the rotation and translation matrix that link the frames of two cameras are calculated by using method of Centroid Distance Increment Matrix. The degree of coupling between the parameters is reduced. Then, 3D coordinates of the calibration points are reconstructed by space intersection method. At last, the reconstruction error is calculated. It is minimized to optimize the calibration parameters. This error directly indicates the efficiency of 3D reconstruction, thus it is more suitable for assessing the quality of dual-camera calibration. In the experiments, it can be seen that the proposed method is convenient and accurate. There is no strict requirement on the calibration plate position in the calibration process. The accuracy is improved significantly by the proposed method.