一种基于局部单应性的投影仪精确标定方法  

Accurate Local Homography-Based Projector Calibration Method

作　　者：孙丽君 张丹丹[1,2,3] 陈天飞 黄志远 李石[1,2,3] Sun Lijun;Zhang Dandan;Chen Tianfei;Huang Zhiyuan;Li Shi(Key Laboratory of Grain Information Processing and Control of Ministry of Education,Henan University of Technology,Zhengzhou 450001,Henan,China;Zhengzhou Key Laboratory of Machine Perception and Intelligent System,Henan University of Technology,Zhengzhou 450001,Henan,China;College of Information Science and Engineering,Henan University of Technology,Zhengzhou 450001,Henan,China)

机构地区：[1]河南工业大学粮食信息处理与控制教育部重点实验室,河南郑州450001 [2]河南工业大学郑州市机器感知与智能系统重点实验室,河南郑州450001 [3]河南工业大学信息科学与工程学院,河南郑州450001

出　　处：《激光与光电子学进展》2022年第13期259-268,共10页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(62173127,61973104);中原科技创新领军人才资助项目(224200510008);河南省优秀青年科学基金(212300410036);河南省高校科技创新人才支持计划(21HASTIT029);河南省高等学校青年骨干教师培养计划(2019GGJS089)。

摘　　要：在条纹投影轮廓术中,投影仪标定作为系统标定的重要组成部分,其标定精度是保证系统测量精度的关键。但投影仪不能直接捕捉图像,无法直接建立目标点与对应投影仪像素点之间的关系,标定过程复杂且精度不高。针对这一问题,分析了投影仪标定的影响因素,提出了一种基于局部单应性矩阵的投影仪标定新方法。首先,通过实验确定局部区域的最佳尺寸;然后,计算圆心所在区域的局部单应性矩阵,完成投影仪坐标的映射;最后,采用相机标定方法完成投影仪的标定。实验结果表明,该方法减小了圆心偏差和相位误差对投影仪标定精度的影响,并基于局部线性化的思想,建立了相机图像坐标到投影仪图像坐标的亚像素级映射,提高了投影仪标定的精度。In fringe projection profilometry,projector calibration is an important part of system calibration.Accurate projector calibration is key to ensuring the accuracy of three-dimensional shape measurements.The profilometry projector cannot capture the image directly.Thus,obtaining the correspondence between pixels and object points is difficult,which makes projector calibration complex with low precision.To address this problem,we analyzed the factors that influence projector calibration and presented a new projector calibration method based on local homography matrix.First,we conducted experiments to determine the optimum size of the local area.Then,we calculated the local homography matrix of the area where the center of the circle is located and completed the mapping of the projector's coordinates.Finally,we used the camera calibration method to calibrate the projector.Experimental results show that this method reduces the influence of center deviation and phase error on the calibration accuracy of the projector.Based on the idea of local linearization,the subpixel mapping of camera image coordinates to projector image coordinates is established,and the accuracy of projector calibration is improved.

关 键 词：测量 条纹投影轮廓术 投影仪标定 局部单应性 圆心偏差 双四步相移 

分 类 号：TN247[电子电信—物理电子学]