Microscopic spectral imaging using a video camera

A technique is described which permits the simultaneous acquisition of multiple fluorescent emission and/or absorption spectra from discrete regions of a specimen under microscopic observation. The instrument consists of a modified inverted microscope, an optical diffraction grating, a silicon intensified target (SIT) camera, and a digital video image processor. Observation of the zero diffraction order of the grating with the SIT camera permits an optical slice of the specimen to be selected by positioning the region of interest over the entrance slit of the grating housing. To obtain the spectral characteristics of this optical slice, the grating is rotated to impinge the first order diffraction on the camera. The video image of this first order diffraction maintains spatial integrity along the slit's long axis and provides spectral dispersion on the perpendicular axis. Thus, each of the horizontal video lines along the long axis of the slit represents a spectral analysis of the corresponding spatial location within the specimen. The spectral resolution (0.2 nm/channel) of each video line is determined by the resolution of the camera system in conjunction with the resolution of the grating. The image processing system acquires and processes all 500 spectra in 33 ms and permits the accurate localization of the source of each spectrum in the slice. This type of topological spectral analysis permits the determination of both spatial and spectral characteristics of intrinsic or extrinsic chromophores within the specimen. In addition, this technique permits the detection of and the possible correction for photobleaching, light scattering and image plane effects. The application of this technique to the study of single cells is discussed and an example of the technique in determining the fluorescence spectra of acridine orange within the nucleus of an intact mammalian blastocyst is described.     

TDICCD相机的低噪声视频处理技术

建立了TDICCD相机系统的噪声模型,分析了TDICCD视频信号读出复位噪声的产生机理,讨论了相关双采样技术的工作原理;给出了TDICCD相机视频处理电路各个组成部分的设计,并进行了分析。在此基础上设计了科学级TDICCD相机。实验结果表明,该视频处理电路在本身引入噪声较小的同时,有效地抑制了暗电流噪声、复位噪声、1／f噪声等,数据输出速率在55MHz时,整机信噪比（S／N）在50dB以上。     

面阵图像传感器在位移测量中的应用研究

在位移测量中,探索采用普通面阵ＣＣＤ取代线阵ＣＣＤ显得具有重大实用价值。本文将讨论微型ＣＭＯＳ电视摄像机作为图像卖座器在实时光电位移测量时的处理生能分析。理论和实际测试结果表明,在体积、成本、测量精度和抗干扰能力等方面,面阵图像传感器都优于线阵ＣＣＤ。     

Single-fluorophore imaging with an unmodified epifluorescence microscope and conventional video camera

Single fluorophores in aqueous solution were imaged in real time with a conventional silicon-intensified target video camera connected to an unmodified commercial microscope (IX70, Olympus) with epifluorescence excitation with a high-pressure mercury lamp. Neither a powerful laser nor an extremely sensitive video camera was required. Three experimental systems were used to demonstrate quantitatively that individual, moving or stationary Cy3 fluorophores could be imaged with the microscope: Cy3-gelsolin attached to an actin filament sliding over heavy meromyosin, sliding actin filaments sparsely labelled with Cy3, and heavy meromyosin labelled with one or two Cy3 fluorophores. The results should encourage many laboratories to attempt 'single-molecule physiology' in which the functions and mechanisms of molecular machines are studied at the single-molecule level in an environment where the biological machines are fully active.     

基于以太网的数字摄像机硬件接口设计

为实现数字化和网络化的视频监控,采用了专用音/视频压缩芯片和DSP芯片,及UDP数据报多播传输方式,完成了基于以太网的嵌入式数字摄像机的硬件接口设计及相应通信协议的设计,实现了全实时同步音/视频采集、压缩、存储和网络传输.研究结果表明,多媒体数据通信的实时性、连续性较好,并可实现多台计算机接收同一数字摄像机发出的图像、声音数据.     

Detection of kinematics parameters of index finger movement with high-speed video camera

Synergic movement of finger＇s joints provides human hand tremendous dexterities, and the detection of kinematics parameters is critical to describe and evaluate the kinesiology functions of the fingers. The present work is the attempt to investigate how the angular velocity and angular acceleration of the joints of index finger vary with respect to time during conducting a motor task. A high-speed video camera has been employed to visually record the movement of index finger, and miniaturized （5-mm diameter） reflective markers have affixed to the subject＇s index finger on the side close to thumb and dorsum of thumb at different joint landmarks. Captured images have been reviewed frame by frame to get the coordinate values of each joint, and the angular displacements, angular velocities and angular acceleration can be obtained with triangle function. The experiment results show that the methods here can detect the kinematics parameters of index finger joints during moving, and can be a valid route to study the motor function of index finger.     

The measurement of discharge using a commercial digital video camera in irrigation canals

This paper presents measurements of the discharge by image techniques on the surface velocity field and water stage in irrigation canals. The velocity and stage gauge are obtained from a commercial digital video camera. The time series of the surface velocity and stage were collected simultaneously. Particle image velocimetry (PIV) was used to determine the surface velocities in the irrigation canal. PIV proceeds by using bubbles floating on the water surface as tracer particles, and making a cross-correlation analysis between two continuous images. The whole surface velocity distribution in the irrigation canals can be obtained. The water stage of the canal is obtained from the digital video camera images by making use of image segments to separate the stage gauge and the background. The discharge is computed by using the surface velocities and water stage via open channel velocity distribution theory. Comparing the discharge measured using image techniques with Parshall flume data shows that the differences are less then 5%. The results suggest that the image measurement techniques developed can be used in applications to estimate the discharge in irrigation canals effectively.     

高速摄像技术在煤粉燃烧工作状态监控中的应用研究

针对高炉喷煤风口监控手段落后和回旋区耦合传热计算误差大、实时性差等问题，本文以高速摄像机作为测试工具，研究了喷煤高炉风口回旋区煤粉燃烧状态。用图像处理和三基色辐射测温法计算回旋区煤粉燃烧的温度变化和相对亮度变化，监控喷吹到高炉的煤粉粒子燃烧工况。并针对高速摄像机CCD传感器在高温测试过程中由于辐射强度过大易出现输出过饱和电流，导致“图像发白”问题，提出了摄像机快门控制模型，以提高摄像机测温动态范围，实现了风口回旋区温度和燃烧脉动的动态测量。通过现场应用表明，该方法为高炉喷煤提供了有力的测试手段和信息来源，快门控制模型提高了温度测量区间。     

绕光轴旋转拍摄LCD上平面靶标实现相机标定

针对在相机标定过程中传统的图像拍摄方法需要拍摄很多幅图像的问题,本文采用绕相机光轴旋转拍摄LCD屏幕上的平面靶标的方法,以利用少量图像获取较高的标定精度.通过对显示在LCD屏幕上的一个具有不同大小圆形特征点的标定表绕相机光轴旋转拍摄几幅图像,利用亚像素边缘轮廓检测算法检测图像中的轮廓,采用最小二乘椭圆拟合方法得到亚像素椭圆中心坐标,在Zhang的算法的基础上考虑切向畸变系数进行相机参数的计算,计算过程中对所求参数进行非线性优化.本方法利用LCD屏幕存在可视角度这一特性以及极高的几何精度和纯平面性的优点,与以往的拍摄标定方法相比较,本方法所需要图像幅数少,仅需3幅图像就可实现标定并得到较高的标定精度.实验表明,重投影平均误差在0.04个像素左右.证明了该标定方法的可行性和高的标定精度.     

计算机视觉中的摄像机标定方法

摄像机标定在三维重建、运动分析以及机器导航等领域中得到了广泛的研究和应用.根据标定技术特点,将摄像机标定分为两大类:基于标定物的摄像机标定和摄像机自标定,介绍了这两大类中典型的摄像机标定方法,回顾了其发展过程,并对各种方法的标定特点以及求解方法进行了分析,最后对摄像机标定方法的未来发展进行了展望.     

智能视频监控关键技术分析

智能视频监控是计算机视觉领域的一个重要的分支。智能视频监控系统中的相关关键技术引起广大学者关注,特别对于运动目标的跟踪和运动目标的检测问题,本文进行相关重点技术探讨,还包括智能视频监控系统中所处的重要位置,对于智能视频监控发展具有一定帮助作用。     

单目OV6620数字摄像头在视觉测距中的应用

单目摄像测距系统在对固定目标的测距中具有精确、灵敏的特点。介绍了使用OV6620数字摄像头借助激光三角测距法实现对目标物的测距原理及实现过程。通过试验证明,该系统在一定条件下可实现有效测距。     

QUADRANT nanosecond four-frame image converter camera

An image converter camera has been developed and manufactured that makes it possible to catch four screen images of an investigated object in the visible spectral range with nanosecond frame exposures and separations.     

Design of echelle spectrograph CCD camera

为了高精度采集中阶梯光栅光谱仪的谱图,设计了一种适用于中阶梯光栅光谱仪原理样机的高性能面阵CCD相机.首先,根据中阶梯光栅光谱仪的谱图特点和CCD芯片的特性,设计了面阵CCD相机的时序产生电路、驱动电路及数据采集处理电路,实现了面阵CCD相机的低噪声、高灵敏度以及高动态范围.然后,利用LabVIEW编写了CCD相机测试软件.最后,利用设计的面阵CCD相机对汞灯谱线进行了测试.结果表明:面阵CCD相机获取的二维谱图图像清晰、信噪比较高;经二维谱图还原后,可以得到标准的汞灯谱线.该相机性能稳定、可靠,满足中阶梯光栅光谱仪原理样机的研制要求.     

高性能CMOS摄像机标定方法研究

针对最新的CMOS摄像机提出了一种新的标定方法,考虑了在摄像机模型中镜头通常会产生的径向畸变和切向畸变,并对现有教材中的坐标变换算法进行了修正,同时提出基于Matlab优化工具箱的简化算法.实验表明,该方法达到很好的标定效果.     

航相机的像移补偿方法及应用

在航相机拍照时不可避免的将产生像移,要提高成像质量和相机分辨力必须进行像移补偿.首先通过分析像移产生的原因及对图像造成的影响阐述了像移补偿的必要性和对像移补偿系统的要求,然后介绍了目前国内外主要采用的像移补偿法原理、实现途径及其应用范围,最后给出了一个应用多种像移补偿方案于同一相机的实例.     

一种单摄像机视觉导引方法

本文提出了一种基于已知固定特征的单目摄像机视觉导引方法,建立了摄像机的运动和投影模型。设计了以正方形顶点为特征的参考平面目标,提出了复杂背景中全自动正方形顶点特征的图像提取新方法及标记特征点的方案。仿真试验表明,摄像机距离参考目标约10m,噪声偏差达到1.5像素时,位置RMS误差小于10cm,姿态RMS误差小于1.4°。因此,所提出的算法具有很强的抗噪声能力,能够满足实时性和实用性要求,为视觉导引的工程应用奠定了理论基础。