{"title":"Improving the quality of extracted endmembers","authors":"Q. Du, Liangpei Zhang, N. Raksuntorn","doi":"10.1109/WHISPERS.2009.5289104","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289104","url":null,"abstract":"Endmember extraction for spectral mixture analysis is a necessary step when endmember information is unknown. If endmembers are assumed to be pure pixels present in an image scene, endmember extraction is to search the most distinctive pixels. Popular algorithms using the criteria of simplex volume maximization (e.g., N-FINDR) and spectral signature similarity (e.g., Vertex Component Analysis) belong to this type. If pure pixel assumption is not imposed, endmember extraction usually is conducted by searching the signatures that can circumscribe the data cloud with the minimum volume. Both types of algorithms are affected by anomalous pixels since such outliers are very different from other pixels and act as interferers during simplex volume evaluation. In this paper, we propose a new approach that separates the endmember searching in normal and anomalous pixels. Real data experiments show that it can improve the quality of extracted endmembers.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114008020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bor-Chen Kuo, Chun-Hsiang Chuang, Chih-Sheng Huang, C. Hung
{"title":"A nonparametric contextual classification based on Markov random fields","authors":"Bor-Chen Kuo, Chun-Hsiang Chuang, Chih-Sheng Huang, C. Hung","doi":"10.1109/WHISPERS.2009.5288978","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5288978","url":null,"abstract":"In this paper a nonparametric contextual classification using both spectral and spatial information will be proposed for hyperspectral image classification. Essentially, among the classification, spatial information is acquired on the basis of Markov random field (MRF) and then joined with the nonparametric density estimation. Two MRF-based nonparametric contextual classifications based on kNN and Parzen density estimation will be introduced. We expect this combination could strengthen the capability for classifying pixels of different class labels with similar spectral values and dealing with data that has no clear numerical interpretation.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125674965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multiple endmember spectral-angle-mapper (sam) analysis improves discrimination of savanna tree species","authors":"M. Cho, R. Mathieu, P. Debba","doi":"10.1109/WHISPERS.2009.5289031","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289031","url":null,"abstract":"Differences in within-species phenology and structure driven by factors including topography, edaphic properties, and climatic variables across the landscape present important challenges to species differentiation with remote sensing. The objective of this paper was to evaluate the classification performance of a multipleendmember spectral angle mapper (SAM) classification approach in discriminating seven common African savanna tree species and to compare the results with the traditional SAM classifier based on a single endmember per species or class. The leaf spectral reflectances of seven common tree species in the Kruger National Park, South Africa, Combretum apiculatum, Combretum hereroense, Combretum zeyheri, Gymnosporia buxifolia, Gymnosporia senegalensis, Lonchocarpus capassa and Terminalia sericea were used in this study. Discriminating species using all training spectra for each species as reference endmembers (i.e. the multiple endmember approach or more conventionally termed Knearest neighbour classifier) yielded a higher classification accuracy of 60% compared to the conventional SAM classifier based on the mean of the training spectra for each species (overall accuracy = 44%). Further analysis using endmembers selected after cluster analysis of all the spectra for each species yielded the highest classification accuracy for the species (overall accuracy = 74%). This study underscores two important phenomena; (i) within-species spectral variability affects the discrimination of savanna tree species with the SAM classifier and (ii) the effect of within-species spectral variability can be minimised by adopting a multiple endmember approach with the SAM classifier. This study further highlights the importance of the quality of the reference endmember or spectral library.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121771259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Autoassociative neural networks for features reduction of hyperspectral data","authors":"F. Frate, G. Licciardi, R. Duca","doi":"10.1109/WHISPERS.2009.5288997","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5288997","url":null,"abstract":"In this paper the potential of neural networks has been applied to hyperspectral data and exploited either for classification purposes or for data feature extraction and dimensionality reduction. For this latter task, a topology named autoassociative neural network has been used. In its complete form, the processing scheme uses a neural network architecture consisting of two stages: the first stage reduces the dimension of the input vector while the second stage performs the mapping from the reduced input vector into the land cover classification. The effectiveness of the feature extraction algorithm has been evaluated for a set of experimental data provided by the AHS radiometer comparing its performance to that obtainable with more traditional linear techniques such as PCA, while the accuracy of the final classification map has been computed on the base of the available ground-truth.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129400350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Weak signal detection in hyperspectral imagery using sparse matrix transform (smt) covariance estimation","authors":"G. Cao, C. Bouman, J. Theiler","doi":"10.1109/WHISPERS.2009.5289043","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289043","url":null,"abstract":"Many detection algorithms in hyperspectral image analysis, from well-characterized gaseous and solid targets to deliberately uncharacterized anomalies and anomalous changes, depend on accurately estimating the covariance matrix of the background. In practice, the background covariance is estimated from samples in the image, and imprecision in this estimate can lead to a loss of detection power. In this paper, we describe the sparse matrix transform (SMT) and investigate its utility for estimating the covariance matrix from a limited number of samples. The SMT is formed by a product of pairwise coordinate (Givens) rotations. Experiments on hyperspectral data show that the estimate accurately reproduces even small eigenvalues and eigenvectors. In particular, we find that using the SMT to estimate the covariance matrix used in the adaptive matched filter leads to consistently higher signal-to-clutter ratios.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"82 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132576361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reducing noise in hyperspectal data — A nonlinear data series analysis approach","authors":"D. Goodenough, T. Han","doi":"10.1109/WHISPERS.2009.5289014","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289014","url":null,"abstract":"Hyperspectral data are subject to a variety of noise sources associated with the physical processes involved during data acquisition, which distort signal statistical properties and limit the applications of hyperspectral data for information extraction. Noise reduction is, therefore, a prerequisite for many hyperspectral data applications based on classification, target identification, and spectral unmixing. Studies have found that hyperspectral data are more complicated than realizations of linear stochastic processes, upon which many hyperspectral noise reduction algorithms are based. The noise in hyperspectral data may be non-Gaussian and signal dependent. Moreover, as demoustrated in our previous work, hyperspectral data exhibit apparent nonlinear characteristics, which suggests that the noise may exist in broad-band in the frequency domain. An algorithm is introduced in this paper with the intention to improve the noise reduction for hyperspectral data. The effectiveness of the algorithm is evaluated using multiple metrics focusing on both noise reduction and spectral shape preservation.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131683221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimal individual supervised hyperspectral band selection distinguishing savannah trees at leaf level","authors":"P. Debba, M. Cho, R. Mathieu","doi":"10.1109/WHISPERS.2009.5289068","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289068","url":null,"abstract":"This paper uses simulated annealing and focus on the spectral angle mapper (SAM), to demonstrate how the separability of two mean spectra from different species can be increased by choosing the bands that maximize the metric. It is known that classification performance is enhanced when the differences in mean spectra for each endmember species are maximized. Comparison was made using the selected bands derived from the proposed method, to all bands in the electromagnetic spectrum (EMS), only the bands in the visible, near infrared and short wave infrared regions of the EMS and selected bands using stepwise discriminant analysis. The bands from the proposed method often indicates a better choice of band selection as viewed by the summary statistics for (a) the SAM measurements, (b) the correlations between bands and (c) the spectral information divergence (SID), for each pair of species; and the classification accuracy of SAM and SID.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115573115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Atmospheric and topographic corrections for hyperspectral imagery","authors":"V. Achard, X. Lenot","doi":"10.1109/WHISPERS.2009.5289098","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289098","url":null,"abstract":"In mountainous areas, slope and altitude variations modulate the airborne sensed hyperspectral radiance image. A new algorithm, SIERRA, has been developed for atmospheric, relief and BRDF corrections in order to extract the surface reflectance in the form of bi-hemispherical albedo that does not depend on solar incidence and observation angles. The forward modeling efforts focus on the estimation of diffuse irradiance and upwelling diffuse radiance, and on the formulation of BRDF effects. The inversion scheme consists of four steps, that go deeper and deeper into the phenomena's complexity. SIERRA is applied to HyMap data. The benefit of topographic correction is clearly demonstrated.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115641757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of mineral (prefered) orientation on composition mapping: Observed in IR range of transmission spectra","authors":"E. Carmina, Carrere Veronique","doi":"10.1109/WHISPERS.2009.5289011","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289011","url":null,"abstract":"Spectra of powdered mineral samples are used for calibration of air-borne data and for quantitative estimation of mineral content. However, in natural environments, minerals can be orientated in a specific manner and their lattices are usually unbroken. Using powders, we minimize orientation effects, but thereby creating a level of uncertainty that should be evaluated. In this study, we attempt primarily to estimate the mineral lattice orientation effect and its expression in spectral signature. The simple case of hornblende-amphiboles (in amphibolites) was observed. An un-mounted thin section, free from epoxy, was prepared, and its transmittance was measured with an FTIR (Fourier Transform Infra-Red) micro-spectrometer in 1–2.5 µm. spectral range. Results show spectral variance caused by mineral (preferred) orientation: changing depth of absorptions, spectral shape and transmittance levels.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117072028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karmon Vongsy, M. Mendenhall, Philip M. Hanna, Jason R. Kaufman
{"title":"Change detection using synthetic hyperspectral imagery","authors":"Karmon Vongsy, M. Mendenhall, Philip M. Hanna, Jason R. Kaufman","doi":"10.1109/WHISPERS.2009.5289016","DOIUrl":"https://doi.org/10.1109/WHISPERS.2009.5289016","url":null,"abstract":"In the best of circumstances, change detection (CD) is accomplished using measurements from the same instrument and under similar collection circumstances. Complications in the CD process arise when the variability in the collection process is not minimized. Variations between collected images and a lack of precise corresponding ground truth make accurate evaluation of a given CD method imprecise at best. This work leverages synthetic hyperspectral imagery, with known ground truth to include primary and tertiary materials, to investigate the use of common CD algorithms for the hyperspectral CD problem. Specifically, we use synthetic hyperspectral images with different spatial resolutions acquired at different altitudes, thus exhibiting different atmospheric affects. The importance of this work is in definition of a CD taxonomy and using that taxonomy for the accurate evaluation of several CD methods. Results are presented using receiver operating characteristic (ROC) curves and the area under the ROC curve, indicating that, under mildly varying imaging conditions, principal component analysis-based CD outperforms simple image differencing and correlation coefficient-based CD methods.","PeriodicalId":242447,"journal":{"name":"2009 First Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124832614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}