共查询到16条相似文献,搜索用时 62 毫秒
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基于统计信号处理技术的贝叶斯(Bayes)估计原理,提出一种新的滤波方法。该方法能有效减少散斑条纹图中的噪声,而且仅用一幅散区斑条纹图就能获得准确的条纹相位分布,通过实例说明了该方法的处理过程。 相似文献
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提出了一种新的应用希尔伯特变换解调干涉条纹相位的算法,可以从单幅干涉条纹图中解调出全场相位分布.在实际应用中,常借助傅里叶变换实现希尔伯特变换算法,但是会忽略负频率成分,造成相位信息的丢失.对于相位分布非单调变化的干涉条纹,提出了一种判断函数,用来计算相位信息零频率点的分布.利用相位的零频率点分布构造了一个二元模板,使用该模板对本文提出的两次希尔伯特变换法产生的包裹相位图进行修正.对修正后的包裹相位图进行解包裹处理,可以得到连续的全场相位分布.对该方法用计算机模拟进行了验证. 相似文献
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在相位测量偏折术(Phase Measuring Deflectometry,PMD)中为获取面形梯度,需要分别获取水平和垂直相移条纹图像,因此所需图像通常较多。为了减少条纹投影幅数,提出一种新的基于复合条纹的相位获取方法,通过将水平和垂直相位信息叠加形成斜条纹,实现基于5幅复合斜条纹的相位获取方法,相位测量精度高于5步正交光栅相移方法。进一步当系统存在非线性响应时,提出了基于7幅斜复合条纹的相位获取方法,可有效消除系统2阶非线性误差。计算机仿真和实验表明所提方法切实可行,其测量精度高于采用同样帧数的正交条纹方法。 相似文献
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ANewFilterTechniqueforImageofElectronicSpecklePatternInterferometricFringe¥DAISongping;MAShining;LIUYing(DepartmentofAppliedP... 相似文献
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相移阴影莫尔条纹正交化解调技术 总被引:1,自引:0,他引:1
提出一种基于克莱姆正则化分析法的三帧自标定相移阴影莫尔三维轮廓技术.该技术首先采用移动光栅的方法获得相移条纹图,然后通过不同帧相移条纹图相减去除条纹图背景,进而结合克莱姆正交化法和最小二乘法,发展了一种相位解调方法,提取了测量相位.以五步Harlharan算法为参考,用不同算法对同一物体表面进行测量.结果表明,相对于典型的三步相移法和主量分析方法,提出的方法测量得到的相位误差最小(0.5rad),且简化了测量过程. 相似文献
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In order to measure the displacements of facets on a growing spherical Cu2−δSe crystal with sub-nanometre resolution, we investigated the reliability and accuracy of standard method of Fourier analysis of digital laser interferograms. Guided by realistic experimental conditions (two-dimensional (2D) interferograms), starting from 2D model interferograms and using original custom designed Gaussian filtering window and multistage unwrapping procedure of the retrieved phase, we demonstrate for a considerable parameter range the non-negligible inherent phase retrieval error due to non-integer number of fringes within the digital image. Our results indicate an intermediate parameter range where the error is acceptably small. We introduce an algorithm modification that significantly reduces the error, especially for low and high fringe densities. In the experimentally most common case of diagonal fringes the reduced error is an order of magnitude smaller than for nearly one-dimensional case within almost entire parameter space. 相似文献
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In response to the comment made by Ferrari on our previous paper [C.J. Tay, C. Quan, F.J. Yang, X.Y. He, Opt. Commun. 239 (2004) 251], we have the following clarifications to make. 相似文献
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Phase unwrapping algorithms, respectively, based on path-following and discrete cosine transform 总被引:1,自引:0,他引:1
This paper describes a path-following phase unwrapping algorithm and a phase unwrapping algorithm based on discrete cosine transform (DCT) which accelerates the computation and suppresses the propagation of noise. Through analysis of fringe pattern with serious noises simulated in mathematic model, we make a contrast between path-following algorithm and DCT algorithm. The advantages and disadvantages of analytical fringe pattern are also given through comparison of two algorithms. Three-dimensional experimental results have been given to prove the validity of these algorithms. Despite DCT phase unwrapping technique robustness and speed in some cases, it cannot be unwrapping inconsistencies phase. The path-following algorithm can be used in automation analysis of fringe patterns with little influence of noise. 相似文献