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Urban-trees extraction from Quickbird imagery using multiscale spectex-filtering and non-parametric classification / Y.O. Ouma in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 3 (May - June 2008)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 63 n° 3 (May - June 2008) . - pp 333 - 351 Titre : Urban-trees extraction from Quickbird imagery using multiscale spectex-filtering and non-parametric classification Type de document : Article/Communication Auteurs : Y.O. Ouma, Auteur ; R. Tateishi, Auteur Année de publication : 2008 Article en page(s) : pp 333 - 351 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] algorithme de filtrage [Termes IGN] analyse multirésolution [Termes IGN] anisotropie [Termes IGN] arbre (flore) [Termes IGN] classificateur non paramétrique [Termes IGN] classification non dirigée [Termes IGN] classification par maximum de vraisemblance [Termes IGN] extraction du sursol [Termes IGN] filtrage non linéaire [Termes IGN] image Quickbird [Termes IGN] milieu urbain [Termes IGN] transformation en ondelettes Résumé : (Auteur) Due to the more heterogeneous spectral-radiometric characteristics within urban land-use/cover units in very-high spatial resolution imagery, the traditional pixel-wise statistical and monoscale based classification approaches do not lead to satisfactory results. The main drawback of these methods is that they neglect the shape and context aspects of the image information, which are among the main clues for information extraction at very-high spatial resolutions. This paper presents a pre-classification filtering strategy based on unsupervised multiresolution non-linear image filtering that combines spectral and textural (spectex) image characteristics. In a multiscale model, the local texture characteristics are extracted via wavelet decomposition. The multiscale wavelets texture is then used to control the multiresolution spectral filtering process using the non-linear anisotropic diffusion approach. From the multiresolution non-linear filtering procedure, scale sub-bands suitable for urban-trees extraction are selected. The selected bands are integrated with a normalized difference vegetation index (NDVI) and a principal components transformation (PCT) for classification using a decision-tree (DT) non-parametric classifier. The DT results are compared with the statistical maximum-likelihood classifier. It has been demonstrated that with Quickbird imagery a classification based on the filtered imagery improved the extraction accuracy of urban-trees by 11.7% using the parametric maximum-likelihood classifier, and by 22.5% using the non-parametric decision-tree classifier. This is an increase from a 70.8% extraction accuracy when the respective methods are not used. The results further indicate that the non-linear filtering approach is superior to the linear (median) filtering technique, by 20.8% with respect to classification accuracy. Copyright ISPRS Numéro de notice : A2008-220 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.10.006 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.10.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29215 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-08031	SL	Revue	Centre de documentation	Revues en salle	Disponible

On the optimization and selection of wavelet texture for feature extraction from high-resolution satellite imagery with application towards urban-tree delineation / Y.O. Ouma in International Journal of Remote Sensing IJRS, vol 27 n°1-2 (January 2006)  

Public [article]  inInternational Journal of Remote Sensing IJRS > vol 27 n°1-2 (January 2006) . - pp 73 - 104 Titre : On the optimization and selection of wavelet texture for feature extraction from high-resolution satellite imagery with application towards urban-tree delineation Type de document : Article/Communication Auteurs : Y.O. Ouma, Auteur ; T.G. Ngigi, Auteur ; et al., Auteur Année de publication : 2006 Article en page(s) : pp 73 - 104 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse texturale [Termes IGN] arbre urbain [Termes IGN] données multiéchelles [Termes IGN] extraction automatique [Termes IGN] extraction de traits caractéristiques [Termes IGN] image à très haute résolution [Termes IGN] image multibande [Termes IGN] image Quickbird [Termes IGN] optimisation (mathématiques) [Termes IGN] texture d'image [Termes IGN] transformation en ondelettes Résumé : (Auteur) Integration of spectral and multi-scale texture is proposed in order to improve the detection and classification of urban-trees from Quickbird imagery. Arguing that spatial -structure semantic information exits at a hierarchy of scales and that texture is a consequence of objects in the hierarchy, multi-scale wavelets decomposition is proposed for the extraction of vertical, horizontal and diagonal texture components. Pre-selection of texture sub-bands is achieved via mean, entropy, variance and second angular moment. The resulting sub-bands are analysed for separability between trees and similarly reflecting features, such as rice-paddy, grass/lawns, open ground and playground, based on KuIlbackLeibler (KL) divergence and Battacharyya distance. The results are ranked and classified with k-means. In comparison with the field data, KL gave the best results with omission and commission error of 4.4%. The proposed methodology has the ability to capture the increased natural variability in reflectance and improved the accuracy by 23.6%, in comparison with spectral-only. Numéro de notice : A2006-059 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160500295885 En ligne : https://doi.org/10.1080/01431160500295885 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27786 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
080-06011	RAB	Revue	Centre de documentation	En réserve L003	Disponible