随机模式投影双目测量系统中的单目测量  

Monocular measurement in binocular measurement system with instantaneous random illumination

作　　者：石春琴[1] 张丽艳[1] 韦虎[1] 刘胜兰[1] 

机构地区：[1]南京航空航天大学江苏省微细与精密制造技术工程研究中心,江苏南京210016

出　　处：《光学精密工程》2010年第1期257-265,共9页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.50875130);国家教育部博士点基金资助项目(No.200802870016);江苏省科技支撑计划资助项目(No.BE2008136)

摘　　要：为克服基于随机模式投影的双目立体测量系统中的局部高光和自身遮挡,提出了一种由单摄像机-投影器构成两个单目测量单元的测量方法。首先,给出了一个标定算法,该算法只需从不同角度拍摄随机光场在普通白板上的图像(称为标定图像),就可以标定纯随机模板上每一点经投影镜头发出的光线,无需标定投影镜头畸变,且精度不受投影镜头畸变的影响。然后,将随机光场照射下的被测物体图像与标定图像进行亚像素精度的像点匹配,根据三角测量原理获取物体表面的三维点云数据。最后,采用标准平面和圆柱面对该方法进行测量精度验证,并给出了具体的测量实例。实验结果表明,标准试件拟合面的平均偏差<0.02mm,测量不确定度<0.05mm(3σ)。综合两个单目测量单元进行测量,能有效避免因高光和遮挡等原因引起的点云数据缺失。To alleviate the effect of local highlight and self occlusion of a random-pattern-projection-based binocular stereo measurement system,a novel method by using a single camera and the projector as a monocular measurement unit was presented.Firstly,a simple and effective calibration algorithm was proposed to construct the line functions of the rays emitted from every point of the random pattern plate through a projector lens,then the calibration was carried out by just taking several images（called calibrated images）of a white board with random illumination in different orientations.It is unnecessary to calibrate the distortion of projector lens,and the system precision is not affected by the distortion.Then,the object image captured in random illumination was matched with the calibrated image at sub-pixel location,and the 3D point cloud data of the object were obtained by triangulation principle.Finally,the standard plane and cylinder were measured to verify the accuracy of the proposed method,which demonstrates that the measurement uncertainty is less than 0.05 mm（3σ）.Several other measurement examples indicate that two monocular measurement units working together can effectively avoid point losing caused by the highlight and occlusion.

关 键 词：双目立体测量 摄像机-投影器 标定 随机光场 三维测量 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]