基于图像处理的自准直检焦方法  

Self-Collimation Inspection and Focusing Method Based on Image Processing

作　　者：李启辉 丁亚林[1] 修吉宏[1] 刘重阳 蔡一铭 廖劲峰 Li Qihui;Ding Yalin;Xiu Jihong;Liu Chongyang;Cai Yiming;Liao Jinfeng(Key Laboratory of Airborne Optical Image and Measurement,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033 China;University of Chinese Academy of Science,Beijing 100049 China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所航空光学成像与测量重点实验室,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《激光与光电子学进展》2020年第2期205-211,共7页Laser & Optoelectronics Progress

基　　金：中国科学院科技创新基金项目(CXJJ-17S017);国家重点研发计划(2017YFC0822403)。

摘　　要：针对传统检焦法复杂度高、稳定性差等问题,提出一种基于图像处理的自准直检焦方法。通过自准直法与图像处理相结合的方法来提高检焦系统的适应性与检焦精度;利用系统离焦距离增大引起成像分辨率降低特性,设计空间频率连续变化的辐射状靶标,避免靶标在系统离焦后对比度变化小的问题。仿真实验选用清晰度评价函数算子计算不同靶标离焦序列图的特征值曲线,结果表明辐射状靶标特征值曲线的灵敏度、无偏性、单峰性均优于Lena图和光栅靶标,且本文检焦法比传统自准直检焦法的检焦精度提高了约19.6%,满足光学系统对离焦量允许值的要求。Traditional inspection and focusing methods have high complexity and poor stability.This paper presents a self-collimation inspection and focusing method based on image processing.The combination of the self-collimation focusing method and image processing method can improve system applicability and inspection and focusing accuracy.An increase in system defocusing distance leads to a decrease in imaging resolution.Radial targets continuously changing in three-dimensional space are designed to avoid the problem of a small change in contrast after defocusing.In the simulation,the evaluation function operator is selected to calculate the characteristic value curves of defocusing sequence graphs of different targets.The results show that the sensitivity,unbiasedness,and unimodality of the characteristic value curves of radial targets are better than those of Lena graphs and raster targets.The self-collimation inspection and focusing method based on image processing improves the precision of the original self-collimation inspection and focusing method by approximately 19.6%,and the required amount of the tolerant defocus is satisfied.

关 键 词：成像系统 航空相机 自动检焦 图像处理 自准直 辐射状靶标 

分 类 号：V241.01[航空宇航科学与技术—飞行器设计] V248.1