共查询到19条相似文献,搜索用时 218 毫秒
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利用小波技术对监测数据进行去噪分析是一种具有广阔应用前景的数据挖掘技术。首先介绍了小波分析的原理与小波变换尺度间去噪方法,在此基础上,应用小波对一组模拟监测数据进行去噪分析,结论显示小波可以用于监测数据的预测分析。 相似文献
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对小波去噪的基本原理和小波阙值去噪方法进行了分析、研究.在此基础上丢小渡阙值去嗓法中阙值函数进行了研究.并针对软、硬阙值函数的不足,提出了一种新阙值函数,并对这个新阙值函数进行分析,并进行试验仿真. 相似文献
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本文系统分析了基于小波变换的门限值去噪方法,研究了小波变换门限值选择的准则及其算法.通过计算机仿真,比较了各种准则的性能,验证了基于小波变换门限值去噪方法的滤波效果.仿真结果表明,基于小波变换门限值的去噪方法可以有效地去除宽带噪声. 相似文献
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利用小波变换消除噪声的方法有多种,如小波模极大值去噪、小波阀值去噪等.本文首先分析小波变换的基本原理,分别对小波变换的模极大值去噪法和阈值去噪法的原理进行阐述,通过计算机仿真表明小波阈值法和模极大值法去噪的有效可行. 相似文献
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采样后的瞬变电磁信号数据容易受到各种噪声的干扰,造成数据处理时分辨率较低,进而出现异常解释信息,影响后续工作进程,因此,必须选取合适的方法对其讲行去噪处理.本文集中对三点指数逼近非线性平滑去噪、基于小波阈值的信号去噪、基于小波变换模极大值的信号去噪、基于小波包的信号去噪等方法及效果进行比较,对瞬变电磁法的去噪工作具有一定的现实意义. 相似文献
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为有效地表现医学图像原有信息中有用的信息,降低医学图像受噪声干扰的现象,减少诊断误差,本文将现有的小波图像去噪方法运用于医学图像,并对各种方法进行实验分析比较,以提供医学参考.实验发现,与较常用的均值滤波与中值滤波相比,小波去噪方法有效提高了医学图像的去噪PSNR值. 相似文献
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瞬变电磁法是当前煤矿电法勘探中最常用的物探方法之一。在瞬变电磁数据采集时,不可避免地受到各种噪声的干扰,传统的去噪方法已不能适应目前的勘探精度要求。通过对一维信号模型加入高斯白噪声进行小波去噪计算机仿真,结果表明小波变换去除高频噪声效果良好。实测资料数据处理结果表明,选择合适的小波簇进行小波分析能有效地区分有用信号与干扰噪声,是一种瞬变电磁信号去噪的可行实用的方法, 相似文献
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《Journal of The Franklin Institute》2018,355(18):9245-9270
This paper deals with noise detection and threshold free on-line denoising procedure for discrete scanning probe microscopy (SPM) surface images using wavelets. In this sense, the proposed denoising procedure works without thresholds for the localisation of noise, as well for the stop criterium of the algorithm. In particular, a proposition which states a constructive structural property of the wavelets tree with respect to a defined seminorm has been proven for a special technical case. Using orthogonal wavelets, it is possible to obtain an efficient localisation of noise and as a consequence a denoising of the measured signal. An on-line denoising algorithm, which is based upon the discrete wavelet transform (DWT), is proposed to detect unavoidable measured noise in the acquired data. With the help of a seminorm the noise of a signal is defined as an incoherent part of a measured signal and it is possible to rearrange the wavelet basis which can illuminate the differences between its coherent and incoherent part. In effect, the procedure looks for the subspaces consisting of wavelet packets characterised either by small or opposing components in the wavelet domain. Taking real measurements the effectiveness of the proposed denoising algorithm is validated and compared with Gaussian FIR- and Median filter. The proposed method was built using the free wavelet toolboxes from the WaveLab 850 library of the Stanford University (USA). 相似文献
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本文提出了一种基于复数小波域上的多方向窗维纳滤波与偏微分方程保持边缘细节相结合的方法。针对小波域维纳滤波的方向性差,本方法先进行复数小波变换,获得六个方向上的图像信号,该六个方向进行方向维纳滤波,对图像进行去噪,以此引导偏微分方程中的扩散函数,实现各项异性进行扩散。实验结果表明,本文所提出的方法的峰值信噪比,以及视觉质量都较复小波去噪或各项异性非线性扩散去噪方法有明显的改善。 相似文献
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Mallat和小波算法在车牌定位系统中的研究 总被引:1,自引:0,他引:1
为了解决含噪车牌图像的定位问题,文章对小波分析在图像的降噪和边缘检测的原理及算法方面进行了深入的研究,在此基础上提出了一种基于Mallat和小波分析的边缘检测和图像分割方法。根据该方法,开发了基于VC++6.0的定位系统,实验结果表明,定位效果好,分割精度高,可以达到98.5%的准确率。 相似文献
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This paper proves a general structural property of the wavelet tree for a given seminorm in the context of the wavelet packet transform method. This structural property can be used in denoising algorithms of different applications to guarantee the optimality of novel search strategies. The property holds for any input signals using any orthogonal analysing wavelet families. The property holds for any norms, which results to be a convex function through the wavelet tree. Using a defined norms, seminorms or pseudonorms, this property can be used to detect incoherent parts of an input signal by using the minimal depth of the tree. In this sense the proposed denoising procedure works without thresholds for the localisation of different kinds of noise, as well as for a stop criterium for an optimal representation of the incoherency. The proof of this property is performed by mathematical induction and the demonstration is based on orthonormality with the help of the multiresolution framework aspects of the wavelets packet tree. The Theorem is independent of the definition of the adopted norm and of the incoherent part of an input signal. In this sense, the discovered property is a general one, which is related to any norm and any nature of the signal incoherence. It can be used in different applications, in which a minimum of a norm is required to be calculated through the wavelet tree. 相似文献
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作为像素级融合的方法之一,小波变换具有多分辨分析和多尺度分析的特点,目前被广泛应用于红外和可见光图像融合中。本文通过深入研究现有的图像融合算法,研究小波基的提升方案,并对其提升处理后的小波性能进行比较。 相似文献
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基于小波网络的电力系统短期负荷预报研究 总被引:7,自引:0,他引:7
本文结合小波和神经网络方法进行电力系统短期负荷预测的通用模型和方法的研究,建立了负荷预报的小波网络模型,确定了有效的算法求解小波函数线性组合的尺度和时延参数以及神经网络的权值。 相似文献