基于Talbot-Moiré法测量透镜焦距的CCD亚像素标定技术  

Sub Pixel Calibration of Measuring Focal Length of Lens Based on Talbot-Moiré

作　　者：吴玲玲[1,2,3] 吴国俊[1] 仓玉萍[1,2] 陈良益[1] 

机构地区：[1]中国科学院西安光学精密机械研究所,西安710119 [2]中国科学院研究生院,北京100049 [3]西安工业大学光电工程学院测控技术与仪器系,西安710032

出　　处：《光子学报》2010年第10期1896-1900,共5页Acta Photonica Sinica

基　　金：中科院"西部之光"人才培养计划"西部博士资助项目"资助

摘　　要：利用Ronchi光栅的Talbot效应和Moiré条纹测量长焦透镜焦距,根据焦距与莫尔条纹斜率之间的定量关系可求得透镜焦距.分别采用Canny算子和形态学方法对光栅的栅线中心进行像素级定位,再用高斯曲线拟合对其进行亚像素定位.经过对标准条纹的标定,验证了该方法的条纹中心定位误差小于0.1个像素.采用光栅作为系统的自基准对CCD像素当量进行了亚像素标定,为条纹斜率和宽度的计算提供了可靠的测量基准,经过计算,采用这些数据计算的焦距误差为0.10%.The focal length of measured lens can be figured out accurately according to its relation to the slope coefficient of Moiré fringes.An approach is presented to determine the location of grating centre at the level of pixel by Canny operator and detection based on mathematical morphology.The sub pixel localization is presented based on Gauss curve fitting.The localization accuracy is proved less than 0.1 pixel by calibrating the standard fringes.Then the grating is set as the reference to calibrate the equivalent length of CCD pixel to ensure the slope and width measuring of fringes accurate.The error of focal length is 0.10%.

关 键 词：焦距测量 TALBOT效应 莫尔条纹 亚像素 标定 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]