鱼眼成像系统标定技术研究

Research on calibration technology of fisheye imaging system

为了解决目标在大视场鱼眼成像系统中定位精度低的问题,采用了一种基于相机移动标定鱼眼成像系统的研究方法。以固定不动的单个点光源作为标定物,通过电动高精度2维旋转位移台驱动鱼眼成像系统移动,分别记录点光源在鱼眼成像系统中的方位角度和光点在图像中的像素位置,构建鱼眼成像系统标定模型,使点光源成像在图像中的各位置;利用图像有效区域的边缘拟合圆计算出光学中心,并采用分区域标定的方式计算出畸变参数,减小标定误差。结果表明,当划分为三区域标定时,该方法在中心成像区域的标定误差为0.06°,精度较高。此研究可应用于红外地球敏感器、广角成像侦查系统等领域中对大视场鱼眼成像系统的标定。

In order to solve the problem of poor target localization accuracy in a large field of view fisheye imaging system,a research method based on camera movement to calibrate the imaging model of the fisheye imaging system was adopted.The calibration object was a single fixed point light source,and the fisheye imaging system was driven to move by a motorized high-precision 2-D turntable to record the orientation angle of the point light source in the fisheye imaging system and the pixel position of the light point in the image,respectively,to construct a calibration model of the fisheye imaging system so that the point light source was imaged at each position in the image;the optical center was calculated by using the edge-fitting circle of the effective area of the image,and the aberration parameters were calculated by using the sub-regional calibration method to reduce the calibration error.The results show that when divided into three regions for calibration,the calibration error of the method in the central imaging region is 0.06°.This method has a high accuracy and can be applied to the calibration of large field-of-view fisheye imaging systems such as infrared earth sensors and wide-angle imaging reconnaissance systems.