共查询到19条相似文献,搜索用时 156 毫秒
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本文将等差载波位相调制原理与夹层全息术结合形成的混合光载波法,可同时获得等差载波条纹图与混合载波条纹图.对混合载波纹图进行光学付里叶变换,利用空间滤波技术可将等和载波条纹从中分离出来.利用图象处理技术实现了对两种载波条纹图从预处理到应力计算的自动化处理.将混合光载波法应用于动态全息光弹性,分离了动态主应力. 文中还提出了一个经济实用的大尺寸载波片制作技术. 相似文献
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本文提出了光载波条纹图的锁相处理方法,以对光载波条纹图作精确定位。给出了适合于计算机处理的离散递归实现步骤。在非线性模型下对定位精确度作了详细分析。实验结果表明,当暂态影响衰减后,能对条纹图进行精确定位而无稳态误差,对断裂条纹的大范围补偿也取得了较好的效果。 相似文献
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干涉云纹光学倍增方法研究 总被引:2,自引:0,他引:2
本文提出一种干涉云纹的光学倍增方法。通过给由试件变形引起的云纹图施加一定频率的载波条纹,用具有高分辨率的记录介质记录这一附加有载波的云纹图,经处理后,记录介质相当于一个频率较低的转移变形试件栅,把它放到云纹干涉光路系统中作为试件栅,当对称入射的双光束在其上形成的虚参考栅频率为原载波条纹频率的2n倍时,就可以得到倍增为2n倍后的载荷条纹,使相应的测量灵敏度提高2n倍。文中对这一方法进行了理论分析和实验验证。 相似文献
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《实验力学》1986,1(3)
量测挠度的全息干涉图的数字化Gilbert,J.A.,Dudderar,T.D.,Mattys,DR.,Chern.J.H.,Digitization of HolograpicInterferograms for Deflection Measurement.Procedings of The SEM Spring Conferenceon Experimental Mechanios.294—301.本文讨论自动采集和分析全息干涉数据所需的载波条纹技术的基本原理.一个监视二维实时立即处理图片的实用方法.收集载波条纹的背景强度以及变形/载波条纹图,一个高分辨率的电视摄象机/电子组件使得所得的二维光强分布数字化和一个用来快速数据换算和整理的计算机.该系统明 相似文献
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在光测力学中,条纹图正则化是进一步提取条纹位相信息的重要基础。对于散斑条纹图来说,正则化的过程还需能够有效地抑制散斑噪声。本文提出一种基于多通道滤波技术的散斑条纹图正则化方法。通过使用多个Gabor滤波通道对散斑条纹图进行滤波,并且引入与条纹对比度有关的权重因子把各个滤波通道的滤波结果叠加起来,最终得到滤除了散斑噪声的正则化条纹图。数值模拟和实验结果表明,该方法在将散斑条纹图正则化的同时能够有效地滤除条纹图中的散斑噪声,为进一步提取条纹位相奠定了良好的基础。 相似文献
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The magnified cross-section of the LDV probe volume fringe field created on a far screen (image plane) with an imaging lens is examined both analytically and experimentally. It is shown that measurements of the image plane fringe field can be used to quantitatively determine the fringe field existing within the probe volume. Because the fringe spacing in the magnified image is more accessible experimentally, both longitudinal- and lateral-coordinate variations in fringe spacing can be determined, permitting a complete mapping of the fringe field. The detailed knowledge of the fringe field thus obtained allows beam quality, alignment, and fringe uniformity to be evaluated with greater precision than is possible with other techniques.The authors would like to acknowledge C. F. Edwards and R. L. Schmitt for the loan of the beam profiler and for many helpful discussions. This work was performed at the Combustion Research Facility, Sandia National Laboratories, and was supported by the U.S. Department of Energy, Office of Industrial Technologies, Advanced Industrial Concepts Division. 相似文献
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This paper presents a fringe-carrier method that eliminates sign ambiguity of transient moire fringes which can be used to
automatically determine the relative orders. A fringe carrier is preset in the static state of the specimen and the dynamic
in-plane displacements are recorded as the modulation to the frequency of the carrier fringes when the specimen is loaded
by impact. According to a modulating criterion developed from the modulation degree, the fringes of the transient moire patterns
keep monotonical in orders so that they can be automatically encoded in grey levels by a digital image system. The moire orders
purely caused by dynamic loadings are evaluated by subtracting the grey-value of the unmodulated carrier image from that of
the modulated carrier images encoded by their orders. With the subtracted moire orders the strain components can be obtained,
and, correspondingly, the histograms of dynamic displacement moire images are shown with order variation by image-difference.
The project supported by Alexander von Humboldt Foundation of Germany and the National Natural Science Foundation of China 相似文献
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全息干涉条纹图的计算机自动处理与识别 总被引:2,自引:0,他引:2
本文应用数字图象处理与识别技术在IBM-PC/AT微处理计算机图象处理系统上对复杂的全息干涉条纹图进行了自动分析,文中采用二维灰度值检测的方法获取条纹的准峰或谷值二值图形,然后通过细化得到条纹中心,提出了用记忆跟踪算法自动去除毛刺和噪声线段.在用光标进行人机对话标定零级条纹后,可自动识别出其它整数条纹级数.分数级条纹级数可在整数级条纹数据之间进行线性或非线性插值得到.最后给出了全息条纹图分析的实例. 相似文献
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光弹性法是确定应力集中系数的有效手段,在实际工程中应力参数都是通过分析光弹干涉条纹图获得的,由于光弹干涉条纹图的复杂性,且影响成像质量的因素较多,因此如何从光弹干涉条纹图中撇开其复杂性,较高精度的提取骨架线,是一项较困难的工作,本文提出一种由改进的Canny算子对条纹方位图进行直接运算提取光弹条纹骨架线的算法,实验表明此方法对光弹条纹图很有效。 相似文献
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本文提出的数字彩色编码方法,利用数字图像处理技术实现光力学条纹的彩色编码,得到具有特定色序的直观性强的彩色条纹图,并通过对编码彩色条纹图的分析提出了条纹级次的自动识别方法,使彩色编码成为一种更加实用而有效的方法。 相似文献
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Summary A screw comparator has been modified into an automatic interference fringe counting comparator which allows determination of displacements with a precision of 0.25 micron.With a photoelectric setting device the reproducibility of setting on a photographic image of a symmetrical spectral line is about 0.5 micron. Automatic recording of fringe counting numbers and total light absorption by the line image is also provided for. The salient features of the apparatus are described and some results of measurements are discussed. 相似文献
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基于小波分析的条纹图滤波方法 总被引:2,自引:0,他引:2
本文提出了一种新颖的干涉条纹图非线性滤波方法,可以选择性地在频域图像的不同区域选用不同的滤波方式,在滤掉图像中大部分散斑噪声的同时,能够减少信息的损失,使图像的内部边界仍然保持清晰。文中首先简介了正交小波变换的原理,然后介绍了去除散斑噪声的具体算法,最后给出了计算机模拟去噪声的结果 相似文献
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Optical Metrology by Fringe Processing on Independent Windows Using a Genetic Algorithm 总被引:1,自引:0,他引:1
We present a method to retrieve the phase of a fringe pattern based on the window fringe pattern demodulation technique (WFPD).
The overlapped phase similarity criterion is avoided in the proposed method, and it is substituted by a second order smoothness
criterion. The fringe processing on independent windows (FPIW) method can measure physical quantities from closed and near
sub-sampled fringe patterns by a simplified cost or fitness function. The fringe image is divided into a set of partially
overlapping windows. In these sub-images the estimated phase is modelled as a parametric analytic-function, and its parameters
are optimized using a genetic algorithm (GA). This analytic-function is used to estimate the phase in the area framed by the
window. Phases from all windows are sequentially spliced to retrieve the whole phase field. A media filter is applied over
the entire phase field to smooth the irregularities that appear in the junctures between windows. 相似文献