基于几何投影的线扩展函数算法研究  

Line Spread Function Algorithm Research Based on Geometrical Projection

作　　者：谢巍[1] 侯丽伟[1] 许春[1] 潘鸣[2] 

机构地区：[1]中国科学院上海技术物理研究所,上海200083 [2]中国电子科技集团公司第五十研究所,上海200063

出　　处：《激光与光电子学进展》2011年第2期24-29,共6页Laser & Optoelectronics Progress

摘　　要：线扩展函数测试是光学成像系统成像质量评价中最重要的一部分,线扩展函数测量精度的高低直接影响到系统调制传递函数(MTF)曲线的测量精度。为了提高线扩展函数的测量精度,提出了一种基于几何投影的线扩展函数测试算法。从算法的原理分析入手,通过感兴趣区域(ROI)截取、狭缝确认及投影计算,拟合得到线扩展函数曲线。用中波红外探测器对黑体背景下的狭缝成像来对算法进行验证,与传统横狭缝测线扩展函数的方法进行对比,分析非均匀性噪声对测量结果的影响,最后对算法的误差来源进行了分析。结果表明,本算法提高了线扩展函数的测量精度,影响测量误差的主要因素是成像系统的信噪比。The line spread function （LSF） testing is the most important part of image quality assessment of optical imaging system.The measuring precision of LSF straightly affects the modulated transfer function （MTF） curve of system.A LSF testing algorithm based on geometrical projection is proposed to raise measuring precision.The LSF fitting curve is gained by analyzing the algorithm,cutting region of interest （ROI）,identifying narrow slit and computing projection.The algorithm is validated by imaging narrow slit with background of a blackbody using a medium wave infrared detector.The results are compared with that using traditional way.The impact of un-uniformity noise on measuring results is analyzed.The main error of the algorithm is analyzed.It is concluded that the algorithm raises the measuring precision and the main factor of measuring error is the signal to noise ratio （SNR） of imaging system.

关 键 词：成像系统 调制传递函数 线扩展函数 几何投影 误差分析 

分 类 号：O434.3[机械工程—光学工程]