共查询到17条相似文献，搜索用时 656 毫秒
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光谱匹配分类方法以光谱相似性测度为分类准则,一种相似性测度只对应于光谱曲线的一种特征,用于光谱匹配分类效果并不好;组合不同类型的相似性测度能够有效改善分类效果,但光谱匹配分类往往忽略了相邻像元间的相关性。为了更好地利用空间信息,提高光谱匹配分类精度,首先组合欧氏距离测度和相关系数测度,得到欧氏距离-相关系数测度;其次通过加入空间乘子,得到结合空间信息的欧氏距离-相关系数测度,从而在光谱匹配分类中增加了空间信息约束。采用两组高光谱影像进行实验验证,结果表明,相比于单一相似性测度及组合相似性测度,结合空间信息的欧氏距离-相关系数测度用于光谱匹配分类能够有效改善分类精度。 相似文献
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讨论了信息熵和均匀光谱间隔(USS)两种无监督高光谱影像波段选择方法,分析比较了基于K均值聚类的欧氏距离、相关系数以及光谱角3种相似性度量。实验表明,利用USS对高光谱影像降维,采用将欧氏距离作为相似性度量的K均值聚类方法进行影像分类,所得到的分类结果精度较高,计算时间较短。 相似文献
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Hyperion高光谱影像中的坏线将直接影响后续应用的准确性。针对Hyperion高光谱辐射率数据的特点,考虑影像中坏线像元与邻近像元在空间和光谱上的相似性,提出了一种局部空间-光谱相似性测度（local spectral-spatial similarity measure,LS3M）,以实现对Hyperion高光谱数据的描述和坏线修复。LS3M由空间和光谱两部分的相似性测度构成,前者为欧氏距离度量,后者组合了Canberra距离和光谱相关角（spectral correlation angle,SCA）。考虑到Hyperion高光谱不同波段的辐射率特性,引入信息熵对SCA进行约束。针对相似像元的邻近搜索问题,引入相似度均值与方差对光谱相似性阈值进行动态调整。为验证该方法的有效性,选取了沙漠、草原、森林、城郊、沿海城市和内陆城市6种典型场景的Hyperion高光谱数据进行模拟坏线的定量误差分析和真实坏线的定性评价;通过与邻域均值法及常规光谱相似性测度的对比,证实LS3M法坏线修复精度更高,稳定性更好。 相似文献
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角度分类器与距离分类器比较研究——以盐渍土分类为例 总被引：3，自引：1，他引：3
选择理想的分类器是进行遥感图像自动分类的关键。距离分类器是以已知地物类别的亮度值作为分类基准，通过比较未知类别像元与已知类别像元亮度值间的距离进行分类。角度分类器是以光谱谱线角为分类基准，通过比较n维波段空间中未知类别像元与已知类别像元光谱角度进行分类。本通过上述两种分类器对同一遥感图像进行分类，对两种分类器的分类效果进行了比较。 相似文献
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高光谱图像波段选择需考虑波段信息.传统香农信息熵指标仅考虑图像的组分信息(像元的种类和比例),忽略了图像的空间配置信息(像元的空间分布),后者可由玻尔兹曼熵刻画.其中,Wasserstein配置熵删除了连续像元的冗余信息,但局限于四邻域,本文将Wasserstein配置熵拓展至八邻域.以印度松木试验场和意大利帕维亚大学高光谱图像为例,使用Wasserstein配置熵差异值测度波段相关性,通过非监督次优搜索法确定最优波段组合,并用支持向量机分类.比较基于Wasserstein配置熵差异值、互信息、4种标准化互信息和两种相对熵变体的图像分类精度.结果表明,四邻域和八邻域Wasserstein配置熵差异值均可用于高光谱图像波段选择,当选择少量波段时优势尤为明显,且八邻域整体优于四邻域. 相似文献
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:光谱相似性测度用来衡量像元光谱的相似程度,是高光谱影像光谱匹配分类的重要工具之一,一般通过设置阈值判断像元光谱和参考光谱是否相似来进行分类。在此基础上,本文提出了一种多特征转换的高光谱影像自适应分类方法,实现了各种光谱相似性特征和分类器相结合的一种自适应分类。实验结果表明,本文提出的方法相比于传统的SVM方法,分类的总体精度更高,还可以避免部分传统光谱匹配分类方法中需要专家经验确定分类阈值的复杂过程。 相似文献
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利用MODIS增强型植被指数(EVI)时序数据,基于中国陆地生态系统55种植被类型上的468个测试点和一个测试区进行了实验,综合比较欧氏距离、光谱信息离散度、光谱角余弦、核光谱角余弦、相关系数、光谱角余弦-欧氏距离6种距离测度方法对遥感植被指数时序数据聚类精度的影响,结果表明:相关系数方法的聚类精度最差;光谱角余弦-欧氏距离方法充分利用了植被指数时序数据的曲线幅度和形状特征,在这6种距离测度方法中表现出了最优的聚类效果;只对光谱亮度敏感的欧氏距离方法或只对曲线形状敏感的光谱角余弦方法,无论是在区分地物类型方面,还是在区域应用上,表现效果均较差;核光谱角余弦虽然在点数据测试上表现较差,但在区域应用上却有较好的表现;光谱信息离散度无论是在点数据测试上还是在区域应用上均表现出了较为适中的效果。 相似文献
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辐射归一化旨在减小不同时相遥感影像间因获取条件不一致而导致的非地表辐射变化的差异,是土地覆盖变化监测的重要前提条件。本文根据高光谱图像上同类地物的谱形及数值的相似性,利用光谱角距离(SAD)和欧氏距离(ED)双重判定选取不变特征点,提出了一种基于光谱角—欧氏距离的辐射归一化方法。在评价指标中除了常用的均方根误差和相对偏差,更增加了高光谱特色的衡量光谱保真性指标:皮尔森系数、光谱扭曲程度。利用高光谱遥感CHRIS图像对本文提出方法进行验证,并与基于多元变化检测(MAD)的辐射归一化方法比较。结果表明,本文方法不仅在辐射特性上优于基于多元变化检测(MAD)的方法,而且具有保持光谱特性的优势,具有较好的应用前景。 相似文献
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提出了动态调整权重的光谱匹配测度的分类方法，它可以根据不同影像、不同分类目的等自适应调整光谱距离和光谱形状测度在分类中的权重，从而达到正确分类的目的。通过对高光谱影像分类的试验，验证了该方法的正确性。 相似文献
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Effectiveness of SID as Spectral Similarity Measure to Develop Crop Spectra from Hyperspectral Image
Hasmukh J. Chauhan B. Krishna Mohan 《Journal of the Indian Society of Remote Sensing》2018,46(11):1853-1862
The present study was undertaken with the objective to check effectiveness of spectral information divergence (SID) to develop spectra from image for crop classes based on spectral similarity with field spectra. In multispectral and hyperspectral remote sensing, classification of pixels is obtained by statistical comparison (by means of spectral similarity) of known field or library spectra to unknown image spectra. Though these algorithms are readily used, little emphasis has been placed on use of various spectral similarity measures to develop crop spectra from the image itself. Hence, in this study methodology suggested to develop spectra for crops based on SID. Absorption features are unique and distinct; hence, validation of the developed spectra is carried out using absorption features by comparing it with field spectra and finding average correlation coefficient r?=?0.982 and computed SID equivalent r?=?0.989. Effectiveness of developed spectra for image classification was computed by probability of spectral discrimination (PSD) and resulted in higher probability for the spectra developed based on SID. Image classification was carried out using field spectra and spectra assigned by SID. Overall classification accuracy of the image classified by field spectra is 78.30% and for the image classified by spectra assigned through SID-based approach is 91.82%. Z test shows that image classification carried out using spectra developed by SID is better than classification carried out using field spectra and significantly different. Validation by absorption features, effectiveness by PSD and higher classification accuracy show possibility of new approach for spectra development based on SID spectral similarity measure. 相似文献
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高光谱遥感光谱相似性度量算法与若干新方法研究 总被引：3，自引：0，他引：3
提出了一种新的光谱相似性度量算法分类体系。在归纳算法的基础上，根据不同的度量原理与实现簋略，结合应用需求，提出了基于光谱多边形的测度、四值编码、十进制编码、树状变换测度及基于小波变换的测度等新方法，这些方法能够应用于分类、检索等的相似性度量中。 相似文献
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Rama Rao Nidamanuri 《国际地球制图》2016,31(8):845-859
Modern hyperspectral imaging and non-imaging spectroradiometer has the capability to acquire high-resolution spectral reflectance data required for surface materials identification and mapping. Spectral similarity metrics, due to their mathematical simplicity and insensitiveness to the number of reference labelled spectra, have been increasingly used for material mapping by labelling reflectance spectra in hyperspectral data labelling. For a particular hyperspectral data set, the accuracy of spectral labelling depends considerably upon the degree of unambiguous spectral matching achieved by the spectral similarity metric used. In this work, we propose a new methodology for quantifying spectral similarity for hyperspectral data labelling for surface materials identification. Developed adopting the multiple classifier system architecture, the proposed methodology unifies into a single framework the differential performances of eight different spectral similarity metrics for the quantification of spectral matching for surface materials. The proposed methodology has been implemented on two types of hyperspectral data viz. image (airborne hyperspectral images) and non-image (library spectra) for numerous surface materials identification. Further, the performance of the proposed methodology has been compared with the support vector machines (SVM) approach, and with all the base spectral similarity metrics. The results indicate that, for the hyperspectral images, the performance of the proposed methodology is comparable with that of the SVM. For the library spectra, the proposed methodology shows a consistently higher (increase of about 30% when compared to SVM) classification accuracy. The proposed methodology has the potential to serve as a general library search method for materials identification using hyperspectral data. 相似文献
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A major reason for the spectral distortions of fused images generated by current image-fusion methods is that the fused versions of mixed multispectral (MS) sub-pixels (MSPs) corresponding to panchromatic (PAN) pure pixels remain mixed. The MSPs can be un-mixed spectrally to pure pixels having the same land cover classes in a fine classification map during the fusion process. Since it is difficult to produce such a land cover classification map using only MS and PAN images, a Digital Surface Model (DSM) derived from airborne Light Detection And Ranging data were employed in this study to facilitate the classification. In a novel fusion method proposed in this paper, MSPs near and across boundaries between vegetation and non-vegetation are identified using MS, PAN, and normalized Digital Surface Model (nDSM). The identified MSPs then are fused to pure pixels with respect to the corresponding land cover class in the classification map. In a test on WorldView-2 images over an urban area and the corresponding nDSM, the fused image generated by the proposed method was visually and quantitatively compared with fused images obtained using common image-fusion methods. The fused images generated by the proposed method yielded minimal spectral distortions and sharpened boundaries between vegetation and non-vegetation. 相似文献
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This study presents a deep extraction of localized spectral features and multi-scale spatial features convolution (LSMSC) framework for spectral-spatial fusion based classification of hyperspectral images (HSIs). First, adjacent spectral bands are grouped based on their similarity measurements, where the whole hypercube is partitioned into several sub-cubes, each corresponding to one band group. Then, the proposed localized spectral features extraction (LSF) strategy is used to extract localized spectral features, which are extracted from each band group using the 1D convolutional neural network (CNN). Meanwhile, the proposed HiASPP strategy is employed to extract the multi-scale features from the first several principal components of each sub-cube. Finally, the extracted spectral and spatial features are concatenated for spectral-spatial fusion based classification of HSI. Experiments conducted on three publicly available datasets have demonstrated that the proposed architecture outperforms several state-of-the-art approaches. 相似文献