利用异形像元探测器提高空间分辨率  

Enhancing spatial-resolution with detectors of special-shaped pixels

作　　者：刘妍妍[1,2] 张新[1] 徐正平[2,3] 张建萍[1] 王灵杰[1] 王德江[3] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所光学系统先进制造技术中国科学院重点实验室,吉林长春130033 [2]中国科学院研究生院,北京100039 [3]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《光学精密工程》2009年第10期2620-2627,共8页Optics and Precision Engineering

基　　金：中国科学院知识创新工程资助项目(No.O69Y32J060)

摘　　要：为了解决光电系统成像中探测器分辨率低的问题,针对造成探测器分辨率低的两大主要因素—采样率不足及感光区域的低通滤波效应,提出一种基于异形像元探测器的超分辨成像方法。综合现有的超分辨重建技术和减少像元尺寸方法的优缺点,将现有的探测器矩形像元逐一"变形",去除同一位置1/4象限;利用该异形像元探测器阵列获取一序列相互错位1/2像元的欠采样图像;最后利用图像算法计算出这些图像的灰度矩阵信息,重建最终的高分辨图像。该方法可同时提高探测器的采样频率和截止频率,拓展带宽,从而实现高分辨率成像。为了验证该方法的有效性,在试验中选取填充因子100%的46μm×46μm中波红外探测器,利用焦距为6 000 mm、口径为600 mm的红外平行光管和焦距为50 mm的中波红外镜头成像,如果不采用任何技术,物方分辨率为11.04 mm;过采样技术可将分辨率提高1.60倍,物方分辨率为6.9 mm;而采用异形像元探测器超分辨成像方法,在试验中将每个像元都抠掉23μm×23μm后,物方分辨率为3.1 mm。For the overwhelming majority of E-O imaging systems, spatial resolution is strictly limited by the detector. This paper studies the main reasons for the influence of the detector on resolution and proposes an imaging method based on special-shaped detectors to enhance the resolution. It is implemented by two detec- tor-arrays of special-shaped pixel where each pixel is reduced by 25% in size. The multiple mis-registered frames are used to solve the grayscale matrix and reconstruct the super-resolution image in the post detection processing. It presents a theoretical assessment that if a small part of the active area of each pixel is deducted, the frequency-response distribution of the complement will be equal to that of the deducted part independent of the amplitude. To demonstrate the arrangement, a MWIR experiment is undertaken,then two 46μm×46μm linear arrays with a 100% full factor are chosen initially and a quarter each pixel is removed. The result dem- onstrates that the bar-contrast interval is discriminated in an objective space by up to 3.1 mm using an optical system composed of a 6 000 mm f/10 collimator and a 50 mm IR lens. By contrast, it is equivalent to an 11.04 mm with conventional imaging method and 6.9 mm through oversampling technology. The study veri- fies that the most visually pleasing image or some specific information can be captured by system-matching from optics to electronics for better processing, and including some pre-detection and post-detection processing.

关 键 词：超分辨成像 异形像元探测器 像元细分 

分 类 号：TN215[电子电信—物理电子学] TP391[自动化与计算机技术—计算机应用技术]