双侧远心线阵视觉系统的动态扫描成像标定

Calibration of Bi-Telecentric Line Scan Version System for Dynamic Scanning Imaging

目前对于由双侧远心镜头和线阵相机组成的成像系统标定方法的研究较少,尤其是考虑动态扫描情况下的双侧远心线阵成像系统标定。文中首先对线阵相机扫描方向做类投影变换处理,进而结合仿射成像建立了双侧远心线阵成像系统的几何成像模型;之后,分析了影响成像效果的各类畸变因素,包括扫描方向速度波动导致的畸变以及成像镜头畸变;接着,给出了所提成像模型的内外参数求解方法及标定流程;最后,通过真实标定实验和仿真实验对所提方法的有效性进行了验证。结果表明该方法可有效实现双侧远心线阵成像系统行、列两个方向的标定,标定后的重投影误差小于1个像素。

There are few researches on the calibration method of the imaging system composed of bi-telecentric lens and line scan camera,especially considering the calibration of the bi-telecentric with line scan imaging system in the case of dynamic scanning.In this paper,the scanning direction of the line scan camera is processed by projection transformation,and then combined with affine imaging,the geometric imaging model of the line scan imaging system with bi-telecentric is established.After that,various distortion factors that affect the imaging are analyzed,including the distortion caused by the speed fluctuation of the scanning direction and the distortion of the imaging lens.Then,the method for solving the internal and external parameters of the imaging model and the calibration process are proposed.Finally,the effectiveness of the proposed method is verified through real calibration experiments and simulation experiments.The results show that this method can effectively achieve the calibration of the row and column directions of the bi-telecentric linear scan imaging system,and the reprojection error after calibration is less than 1 pixel.