摄像机景深及其运用

本文基于摄像机景深的基本理论剖析,对标清摄像机与高清摄像机的景深比较分析和计算,从而掌握景深与摄像机相关参数的依存关系;并在实际拍摄中实现电视画面构想中的景深控制,完成画面创作。     

固体摄像机性能评价与质量检测技术研究──几何失真度测量

摄像机镜头前的电视线性测试卡（圆圈格子卡，又名球卡，国际GB6996.2—86）上的标准图象与摄像机输出图象之间的几何误差称为几何失真度。它是因摄像管扫描误差和镜头的几何畸变引起的摄像机输出的图象误差。阑14加方甚用模母阿卜的给什测付网模似测试方法是将电视线性测试卡的图象和方格子信号发生器产生的方格子图象二者叠加在一起，以方格子作为标准坐标，去判别小圆圈偏离方格子交叉点的距离，然后用人眼判别几何失真度。由于小圆圈个数多（144个），方格子与小圆圈重叠不理想，圆圈和方格子边界都有模糊的地方。因此目视观察难以准确…     

三代微光器件的测试和评估技术研究

在已有的负电子亲和势(NEA)光电阴极特性评估技术的基础上,研制了三代微光器件的测试和评估系统工程样机,用于对三代微光器件的光谱响应等参数的测试和激活过程中的工艺信息监控,通过分析计算可获得三代微光器件光电阴极的表面逸出几率、载流子扩散长度和后界面复合速率等参数.利用该系统对三代微光像增强器进行了测试和评估,文中给出了测试结果并加以分析.     

水中弹道测试的数据处理技术

水中高速运动弹丸的测试不同于空气中测试,由于水中运动的弹丸的速度降很大,而且是非线性的,因此常规的区截靶测试和光电测试等方法都无法准确测试弹丸的运动轨迹及速度、加速度和转速等参数．但由于水中弹道及运动规律、水中弹丸受力和阻力系数的测量又迫切要求知道弹丸的精确运动规律,因此需要研究水中弹道参数的精确测试技术．本文介绍了一种数据处理方法,使用高速摄像测量技术和图像处理方法,利用样条拟合方法,可在亚像素精度上确定弹丸的位置等参数．该方法可以有效地解决水中弹道数据的测量问题．     

光电稳定跟踪平台跟踪控制回路性能测试系统

针对光电稳定跟踪平台跟踪性能测试困难的问题,依据光电产品跟踪系统的特点,设计一套光电平台跟踪控制回路性能测试系统。该系统中将运动物体放置在平行光管或者凹面反射镜的焦面处,通过控制物体的运动规律模拟无穷远处运动目标,实现在实验室内对跟踪角速度、跟踪角加速度等指标的测试。实验表明该系统结构简单,测试准确、方便,测试效率高。     

特殊用途摄像机和常用的特殊摄像手段

特殊用途摄像机是指除了用于广播电视外,还具有其它用途,如用于工业、航天探测、水下摄影等领域的摄像机。特殊摄像手段是常规摄像手段的有益补充,丰富了电视摄像造型技巧。本文主要介绍几种特殊用途摄像机和五种特殊摄像手段。     

负电子亲和势光电阴极评估技术研究

阐述了负电子亲和势（NEA）光电阴极的评估原理,用NEA光电阴极的量子产额理论曲线对测试获得的实验曲线进行拟合,可以获得光电阴极的表面逸出概率、载流子扩散长度和后界面复合速率等参数。介绍了NEA光电阴极激活和评估系统,利用该系统对国产的反射式GaAs基片进行了激活和评估,文中给出并分析了测试结果。     

负电子亲和势光电阴极评估技术研究

阐述了负电子亲和势(NEA)光电阴极的评估原理,用NEA光电阴极的量子产额理论曲线对测试获得的实验曲线进行拟合,可以获得光电阴极的表面逸出概率、载流子扩散长度和后界面复合速率等参数.介绍了NEA光电阴极激活和评估系统,利用该系统对国产的反射式GaAs基片进行了激活和评估,文中给出并分析了测试结果.     

照明弹终点效应测试

照明弹终点效应测试需要测试的参数主要包括照明剂的有效燃烧时间、照明弹的空爆高、开伞高、熄火高、照明系统的下滑速度等.目前测试爆高、开伞高和熄火高主要使用高炮指挥镜或电视经纬仪,测试照明剂的有效燃烧时间主要使用秒表.本文依据三角形相似原理,提出了一种非接触式远距离半自动测试方法.在解决距离、高低角和方向角准确测试的基础上,试制了一种照明弹终点效应半自动测试系统,利用该系统进行了初步实弹测试,结果表明本文提出的测试原理是正确的,在此基础上试制的照明弹终点效应测试仪具有测试结果可靠、性能稳定特点.     

带切向畸变的模型可视化摄像机标定

根椐Tsai两步标定方法,在Matlab中首先运用直接线性变换法(DLlr)对摄像机参数进行估计,然后以线性参数为初始值,运用非线性优化方法对摄像机参数进行优化.并对摄像机参数标定过程中的畸变模型进行分析,主要分析了透镜的径向和切向畸变分量.最后根据标定的摄像机参数,实现了摄像机畸变模型可视化.     

Automation of reading liquid-in-glass thermometers

In this paper, the automation of calibration of liquid-in-glass thermometers (LiGTs) is discussed. Temperature readings are taken automatically with the use of a measuring system that consists of a standard calibration setup, a video camera and illumination, an image acquisition module and a computer that executes the algorithm for image processing and analysis. Once the reading of the temperature is extracted from the acquired image, this value can be passed to any other data processing program, which includes the comparison with the values from the reference thermometer and determination of correction and combined uncertainty. Data achieved in this way can be directly used to prepare the calibration certificate     

Axi-vision camera (real-time distance-mapping camera)

The camera described here makes color TV images that include information about the distance between the camera and the objects in the images. This range information is obtained from two images of the same scene taken under different illumination conditions. The camera does not require scanning, multiple camera units, or complicated computation. Range information for each pixel is acquired fast enough to keep up with the video rate of a TV camera. We describe various operational features and technical specifications such as ranging errors as well as the results of experimental investigations of the dependence on the color and reflectivity of the objects, of the sensitivity to interference from external light, and of the effects of the movement of the objects.     

Automatic color-temperature compensator with guest-host liquid-crystal filter for video image sensing

A color-temperature compensating system with an electrically controllable liquid-crystal filter and a color sensor mounted on a video camera has been developed for color image sensing. The filter contains two guest-host liquid-crystal devices with dichroic dyes that have strong light absorption for shorter-wavelength light; two devices are necessary because of the spectral difference between the sun and an incandescent lamp as light sources. The filter's absorption is continuously controlled by the voltage applied to the filter. Because the filter is driven according to spectral information about the illumination detected by the color sensor, the color balance of the video image to be sensed can be compensated automatically and rapidly. This is especially useful for video image shooting in which a video camera experiences changes in illumination color temperatures.     

Totally implantable real-time in vivo video telemetry monitoringsystem for implant biocompatibility studies

An implantable real-time video telemetry monitoring system was developed for remote monitoring and evaluation of tissue reactions to an implant such as a biosensor. Experimental coatings and treatments to improve the function of an implant can now be evaluated in situ and in real-time for improved blood vessel growth (angiogenesis), reduced inflammation, and reduction of foreign body encapsulation. A tissue site can be viewed, recorded, and evaluated for a continuous time period without surgical intervention, thereby saving animal lives. The implantable system comprises a miniaturized fiber optic lens-based CCD camera, a TV video transmitter, a 4-LED illumination module, and a 9 VDC battery source. The TV video signal is telemetried out to a TV set or video tape recorder having a tuner. The 512×492 display or printout image pixels represent a 1.6×1.2 mm field of view by virtue of a 1:3 tapered (3X optical magnification) lens. The apparent magnification thus can approach 200 power with a 200 μm resolution (4 μm Nyquist). Test pattern modulation transfer functions showed resolvability at 90.5 1p/mm (5.5 μm line width) for both telemetried and direct captured images. In vivo and ex vivo rat tissue images showed blood vessels with diameters of 5-10 μm. Various tissue types, such as muscle and connective tissues, were distinguishable, as were experimental drug delivery microspheres of 10-20 μm in diameter. Therefore, we conclude that we have developed a new tool to study tissue reactions to implants     

基于TMS320DM642的电视测角仪检测研究

通过分析电视测角仪的检测需求,结合数字图像处理技术,提出了以TMS320DM642为核心的视频检测系统框架,并对主要电路的设计进行了详细的介绍。根据CCD像元与数字图像中像素的对应关系,提出了在数字图像中计算弹标偏移量的处理方案,结合电视测角仪捕捉弹标信号的特点,通过追踪窗口的定位缩小了数据处理范围,提高了检测系统的实时性。整个系统以视频采集系统为基础,以数字图像处理为核心,为电视测角仪的检测研究提供了一种新的思路。     

基于DSP TMS320C6x的实时图象处理系统

以ＤＳＰ ＴＭＳ３２０Ｃ６２０１为核心处理器,设计一种通用的实时图象处理系统。该系统可以满足当前的远程监控、电视电话、会议电视、道路交通管理等诸多视频／图象处理与传输领域应用的需求。文中对系统的硬件资源选择、工作流程、算法处理时间等关键问题进行了详细地讨论。最后以Ｈ．２６１采集、编码系统为例分析了算法的实现过程和系统的实时性能。     

A probabilistic approach for video stabilisation in compressed domain

Machine vision systems, which are being extensively used for intelligent transportation applications, such as traffic monitoring and automatic navigation, suffer from image instability caused by environment unstable conditions. On the other hand, by increasing the use of home video cameras which sometimes need to remove unwanted camera movement, which is created by cameraman shaking hands, video stabilisation algorithms are being considered. The video stabilisation process consists of three essential phases: global motion estimation, intentional motion estimation and motion compensation. Motion estimation process is the main time consuming part of global motion estimation phase. Using motion vectors extracted directly from MPEG compressed video, instead of any other special feature, can increase the algorithm generality. In addition, it provides the facility for integrating video stabilisation and video compression subsystems and removing the block matching phase from video stabilisation procedure. Elimination of any iterative outlier removal preprocessing and adaptive selection of motion vectors has increased speed of the algorithm. Although deterministic approaches are faster than the related probabilistic methods, they have essential problems in escaping from local optima. For this purpose, particle filters, the ability of which is considerable when submitted to non-linear systems with non-Gaussian noises, are utilised. Setting the parameters of the particle filter using a fuzzy control system reduces the incorrect intentional camera motion removal. The proposed method is simulated and applied to video stabilisation problem and its high performance on various video sequences is demonstrated.     

基于差异积累的视频运动对象自动分割

针对视频运动对象的自动分割，本文给出了一种基于差异积累的自动分割算法。与传统的基于运动信息变化检测方法不同，该算法通过累积的帧差信息构建出可靠的背景，与当前帧比较进而提取出视频运动对象。本文提出了一种增强的基于Otsu法的自适应阈值化方法，能更准确地对背景差图像进行阈值化分割，克服了传统Otsu法阈值化容易失效的问题。改进的基于区域生长的定位方法更能避免传统方法的误定位及重定位的问题。实验结果表明，本文算法具有较好的实时性、自适应性以及鲁棒性，可以较为可靠地建立背景模型并进行实时更新，适用于刚体或非刚体存在平缓的光照变化以及摄像头微抖动的视频运动对象的自动分割。     

对光照变化鲁棒的一种运动目标检测方法

鉴于现有的运动目标检测方法对光照变化的敏感性,本文提出了一种在静态场景下对光照变化鲁棒的运动目标检测方法。该方法利用视频当前图像帧的边缘与背景图像的边缘做差分运算,得出运动目标的轮廓,进而对运动目标进行定位与检测。实验证明,本方法在一定程度上能够消除由于环境光照变化引起的"曝光"现象,实时准确地检测出运动目标及其位置,运算速度快,满足实时性的需求。     

Automatic analysis of speckle photography fringes

Speckle interferometry is a technique adequate to metrological problems such as the measurement of object deformation. An automatic system of analysis of such measurements is given; it consists of a motorized x-y plate positioner controlled by computer, a CCD video camera, and software for image analysis. A fringe-recognition algorithm determines the spacing and orientation of the fringes and permits the calculation of the magnitude and direction of the displacement of the analyzed object point in images with variable degrees of illumination. For a 256 x 256 pixel image resolution, the procedure allows one to analyze from three fringes to a number of fringes that corresponds to 3 pixels/fringe.