In flight MTF monitoring and compensation for CCD camera on CBERS-02

All image systems cause a blurring of the scene radiance field during image acquisi- tion. Accurate characterization of this blurring is referred to as the modulation transfer function (MTF)[1]. The MTF is a fundamental imaging system design specification and system quality metric often used in remote sensing. It results from the cumulative effects of the instrumental optics (diffraction, aberrations, focusing error), integration on a pho- tosensitive surface, charge diffusion along the arra…     

多谱段标准镜头光学系统设计及装校

本文设计了一款检测用的多谱段标准镜头,其焦距为180mm、相对孔径D F=13、视场角2ω=6°。该镜头具有波段（400-1000nm）跨度比较宽的特点,并且对每个特定波长的传递函数值都有严格的要求,即在80 lp/mm时均达到0.5以上,且畸变小于2%。设计时运用光学设计软件ZEMAX的多重结构功能,保证了每个特定的波长传递函数都能达到要求。在装校镜头时通过定心仪精调每组镜片与镜筒的同轴度。经过精细的设计及有效的装校,最终产品测试结果表明轴上星点达到非常良好的效果,传递函数全部满足设计要求。     

Evaluation of moving‐line contrast degradation without motion

Abstract— A method for evaluation of the contrast of moving step‐grating patterns under smooth‐pursuit eye‐tracking conditions without imaging data acquisition and image analysis is introduced. Periodic optical responses of the display to a set of simple driving signals have been recorded at a fixed location, and the luminance vs. time data has been evaluated to obtain two types of contrast for characterization of the dynamical performance of the display under test: the frame‐convoluted contrast and the frame‐integrated contrast. The relation of this characterization with respect to modulation transfer functions from impulse responses and to the dynamic modulation transfer function from sine‐gratings is explained and discussed. The approach described here provides a detailed and comprehensive characterization of the dynamical properties of electronic displays including both extreme cases of step‐response and impulse‐response with quantities that are related to visual perception. With this type of evaluation, the visual resolution of displays can be described by the same characteristics in the static and the dynamic case. The method is attractive due to limited instrumental efforts and the transparent method of evaluation.     

TDI-CCD相机动态成像的速度同步控制研究

在介绍时间延迟积分电荷耦合器件(TD I-CCD)的结构与工作原理基础上,通过像移调制传递函数(MTF)分析了TD I-CCD行扫速率与运动像不同步时对相机成像质量的影响。理论和实验仿真表明:在奈奎斯特频率范围内,只要将TD I-CCD推扫成像过程中的同步误差控制在一定的范围内,就可以明显地减少像移对成像质量的影响,最后,给出了2种简便和实用的同步控制方法。     

Development of the PenTile Matrix™ color AMLCD subpixel architecture and rendering algorithms

Abstract— Color subpixel rendering is enhanced by co‐optimizing the color subpixel architecture and algorithms with respect to human vision. This has resulted in the PenTile? display technology, which provides double the information content per subpixel when compared to a conventional RGB Stripe display. Output performance results from mathematical modeling, software simulations, and prototype AMLCDs displays demonstrate significant quality improvements to both text and full‐color images in comparison to images from RGB Stripe displays that have the same number of subpixels and column drivers.     

集成成像技术的像质评价分析

为了研究集成成像非共轭面的成像质量,根据光线追迹原理分析透镜阵列的成像过程,指出三维成像原理并给出不同离焦量下的轴截面成像分辨率;从波动光学角度分析包含离焦波像差的透镜阵列光学传递(OTF),得到集成成像系统的非共轭面调制传递函数(MTF)并指出与单透镜共轭面成像的联系.根据非共轭面分辨率给出符合视觉要求的显示深度计算方法.采用投影仪与菲涅尔透镜搭建显示面积为100×750 mm2的集成成像显示系统,实验结果表明,集成成像轴截面成像分辨率在离焦量增大的情况下迅速下降,非共轭面像质是制约集成成像显示效果的重要因素之一.     

镜头成像畸变的MTF像高测试法研究

为了解决传统标板拍摄测试广角镜头成像畸变的不准确、复现性差问题,提出了基于调制传递函数(MTF)理论的成像畸变测试方法。通过研究镜头畸变测试国内外的研究现状,重点分析了成像镜头特别是广角镜头采用传统标板拍摄测试成像畸变的缺陷。提出了一种通过测试镜头轴上有效焦距和不同角度的离轴有效焦距,并导入畸变计算公式从而得到镜头成像相对畸变的MTF测试方法。研究结果表明,采用MTF测试方法可以实现对镜头成像畸变的快速、准确的测量。     

光电成像系统的分辨率鉴定与测量技术

论述了光电成像系统中广泛使用的分辨率指标及分类,对空间分辨率模拟度量法的原理和测量方法进行了论述和分析。通过研究指出用空间分辨率指标来描述成像系统的质量,具有较好的直观性和归一性。由于单一的空间分辨率测量指标还不可能给出总的图像系统的性能,仅仅基于分辨率指标的图像评估不可能同时保证系统灵敏度设计的技术要求。因此,结合模拟度量法研究光电成像系统的分辨率测量法,给出成像分辨率测量准则。     

Pixel‐Structured Scintillator with Polymeric Microstructures for X‐Ray Image Sensors

We introduce a pixel‐structured scintillator realized on a flexible polymeric substrate and demonstrate its feasibility as an X‐ray converter when it is coupled to photosensitive elements. The sample was prepared by filling Gd₂O₂S:Tb scintillation material into a square‐pore‐shape cavity array fabricated with polyethylene. For comparison, a sample with the conventional continuous geometry was also prepared. Although the pixelated geometry showed X‐ray sensitivity of about 58% compared with the conventional geometry, the resolving power was improved by about 70% above a spatial frequency of 3 mm^?1. The spatial frequency at 10% of the modulation‐transfer function was about 6 mm^?1.     

高能X光闪光照相中CCD相机的MTF

鉴于CCD相机系统在奈奎斯特频率附近出现的较严重的像元对信号的调制现象,提出了一种空间全分辨的概念,对CCD的调制传递函数(MTF)进行了分析.模拟了高能X光闪光照相环境及CCD器件性能参数对CCD的MTF的影响.得出了CCD相机极限分辨率的决定因素是CCD像元尺寸,高能X光闪光照相环境是影响CCD的MTF的重要因素的结论.在CCD像元尺寸受限的情况下,尽量减少高能X光闪光照相环境的影响成为改善CCD相机MTF的最有效途径.