基于两步标定法的稳定、高精度条纹投影三维轮廓重建

Two-step calibration method for accurate and stable 3D shape reconstruction with fringe projection profilometry

在传统的条纹投影轮廓术(FPP)重建算法中,通常倾向于简化校准模型以提高数值稳定性。但是简化后的校准模型难以有效地补偿FPP系统中照相机和投影仪的镜头畸变,结果不能保证FPP的测量精度。提出了一种两步标定法,依次执行镜头畸变补偿和系统标定,通过使用相机和投影仪的标定参数来校正输入变量的值,实现镜头畸变的有效补偿,同时给出形式简洁但精度更高的测量模型进行物体三维轮廓重建。实验结果验证了方法的有效性和实用性。

Generally, simplified calibration models are preferred in existing reconstruction algorithms for fringe projection profilometry(FPP) to improve numerical stability. However, the lens distortions of the camera and the projector of a FPP system cannot be compensated effectively with such a simplified calibration model and the measurement accuracy of FPP cannot be assured as a result. Therefore, a two-step calibration method, in which lens distortion compensation and system calibration are performed successively, is presented. The lens distortion compensation is performed by correcting the values of input variables with calibrated parameters of the camera and the projector. Therefore, lens distortions of the camera and the projector can be compensated effectively, and 3 D shape data with higher accuracy can be retrieved accurately with a concise calibration model. The validity and practicality of the proposed method are verified with experimental results.