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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)
[article]
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 ondelettesRésumé : (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
in ISPRS Journal of photogrammetry and remote sensing > vol 63 n° 3 (May - June 2008) . - pp 333 - 351[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-08031 SL Revue Centre de documentation Revues en salle Disponible Comparison and improvement of wavelet-based image fusion / G. Hong in International Journal of Remote Sensing IJRS, vol 29 n°3-4 (February 2008)
[article]
Titre : Comparison and improvement of wavelet-based image fusion Type de document : Article/Communication Auteurs : G. Hong, Auteur ; Y. Zhang, Auteur Année de publication : 2008 Article en page(s) : pp 673 - 691 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse comparative
[Termes IGN] analyse en composantes principales
[Termes IGN] fusion d'images
[Termes IGN] image Ikonos
[Termes IGN] image Quickbird
[Termes IGN] ondelette
[Termes IGN] transformation en ondelettes
[Termes IGN] transformation intensité-teinte-saturationRésumé : (Auteur) The wavelets used in image fusion can be categorized into three general classes: orthogonal, biorthogonal, and non-orthogonal. Although these wavelets share some common properties, each wavelet also has a unique image decomposition and reconstruction characteristic that leads to different fusion results. This paper focuses on the comparison of the image-fusion methods that utilize the wavelet of the above three general classes, and theoretically analyses the factors that lead to different fusion results. Normally, when a wavelet transformation alone is used for image fusion, the fusion result is not good. However, if a wavelet transform and a traditional fusion method, such as an IHS transform or a PCA transform, are integrated, better fusion results may be achieved. Therefore, this paper also discusses methods to improve wavelet-based fusion by integrating an IHS or a PCA transform. As the substitution in the IHS transform or the PCA transform is limited to only one component, the integration of the wavelet transform with the IHS or PCA to improve or modify the component, and the use of IHS or PCA transform to fuse the image, can make the fusion process simpler and faster. This integration can also better preserve colour information. IKONOS and QuickBird image data are used to evaluate the seven kinds of wavelet fusion methods (orthogonal wavelet fusion with decimation, orthogonal wavelet fusion without decimation, biorthogonal wavelet fusion with decimation, biorthogonal wavelet fusion without decimation, wavelet fusion based on the 'à trous', wavelet and IHS transformation integration, and wavelet and PCA transformation integration). The fusion results are compared graphically, visually, and statistically, and show that wavelet-integrated methods can improve the fusion result, reduce the ringing or aliasing effects to some extent, and make the whole image smoother. Comparisons of the final results also show that the final result is affected by the type of wavelets (orthogonal, biorthogonal, and non-orthogonal), decimation or undecimation, and wavelet-decomposition levels. Copyright Taylor & Francis Numéro de notice : A2008-005 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701313826 En ligne : https://doi.org/10.1080/01431160701313826 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29000
in International Journal of Remote Sensing IJRS > vol 29 n°3-4 (February 2008) . - pp 673 - 691[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-08021 RAB Revue Centre de documentation En réserve L003 Disponible Land-cover classification in the Brazilian Amazon with the integration of Landsat ETM+ and Radarsat data / Dong Lu in International Journal of Remote Sensing IJRS, vol 28 n°23-24 (December 2007)
[article]
Titre : Land-cover classification in the Brazilian Amazon with the integration of Landsat ETM+ and Radarsat data Type de document : Article/Communication Auteurs : Dong Lu, Auteur ; M. Batistella, Auteur ; E. Moran, Auteur Année de publication : 2007 Article en page(s) : pp 5447 - 5459 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte
[Termes IGN] Amazonie
[Termes IGN] analyse texturale
[Termes IGN] Brésil
[Termes IGN] classification par maximum de vraisemblance
[Termes IGN] fusion d'images
[Termes IGN] image Landsat-ETM+
[Termes IGN] image multibande
[Termes IGN] image optique
[Termes IGN] image panchromatique
[Termes IGN] image radar
[Termes IGN] image Radarsat
[Termes IGN] niveau de gris (image)
[Termes IGN] occupation du sol
[Termes IGN] transformation en ondelettes
[Termes IGN] zone tropicale humideRésumé : (Auteur) Land-cover classification with remotely sensed data in moist tropical regions is a challenge due to the complex biophysical conditions. This paper explores techniques to improve land-cover classification accuracy through a comparative analysis of different combinations of spectral signatures and textures from Landsat Enhanced Thematic Mapper Plus (ETM+) and Radarsat data. A wavelet-merging technique was used to integrate Landsat ETM+ multispectral and panchromatic data or Radarsat data. Grey-level co-occurrence matrix (GLCM) textures based on Landsat ETM+ panchromatic or Radarsat data and different sizes of moving windows were examined. A maximum-likelihood classifier was used to implement image classification for different combinations. This research indicates the important role of textures in improving land-cover classification accuracies in Amazonian environments. The incorporation of data fusion and textures increases classification accuracy by approximately 5.8-6.9% compared to Landsat ETM+ data, but data fusion of Landsat ETM+ multispectral and panchromatic data or Radarsat data cannot effectively improve land-cover classification accuracies. Copyright Taylor & Francis Numéro de notice : A2007-538 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01431160701227596 En ligne : https://doi.org/10.1080/01431160701227596 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28901
in International Journal of Remote Sensing IJRS > vol 28 n°23-24 (December 2007) . - pp 5447 - 5459[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 080-07131 RAB Revue Centre de documentation En réserve L003 Disponible The wavelet method as an alternative for reducing ionospheric effects from single-frequency GPS receivers / E.M. DE Souza in Journal of geodesy, vol 81 n° 12 (December 2007)
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Titre : The wavelet method as an alternative for reducing ionospheric effects from single-frequency GPS receivers Type de document : Article/Communication Auteurs : E.M. DE Souza, Auteur ; João F.G. Monico, Auteur Année de publication : 2007 Article en page(s) : pp 799 - 804 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie spatiale
[Termes IGN] analyse multirésolution
[Termes IGN] double différence
[Termes IGN] perturbation ionosphérique
[Termes IGN] récepteur monofréquence
[Termes IGN] signal GPS
[Termes IGN] transformation en ondelettesRésumé : (Auteur) The ionospheric effect is one of the major errors in GPS data processing over long baselines. As a dispersive medium, it is possible to compute its influence on the GPS signal with the ionosphere-free linear combination of L1 and L2 observables, requiring dual-frequency receivers. In the case of single-frequency receivers, ionospheric effects are either neglected or reduced by using a model. In this paper, an alternative for single-frequency users is proposed. It involves multiresolution analysis (MRA) using a wavelet analysis of the double-difference observations to remove the short- and medium-scale ionosphere variations and disturbances, as well as some minor tropospheric effects. Experiments were carried out over three baseline lengths from 50 to 450 km, and the results provided by the proposed method were better than those from dual-frequency receivers. The horizontal root mean square was of about 0.28 m (1ó). Copyright Springer Numéro de notice : A2007-526 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-007-0150-4 En ligne : https://doi.org/10.1007/s00190-007-0150-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28889
in Journal of geodesy > vol 81 n° 12 (December 2007) . - pp 799 - 804[article]Exemplaires(2)
Code-barres Cote Support Localisation Section Disponibilité 266-07101 RAB Revue Centre de documentation En réserve L003 Disponible 266-07102 RAB Revue Centre de documentation En réserve L003 Disponible Despeckle and geographical feature extraction in SAR images by wavelet transform / Karunesh K. Gupta in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 6 (November-December 2007)
[article]
Titre : Despeckle and geographical feature extraction in SAR images by wavelet transform Type de document : Article/Communication Auteurs : Karunesh K. Gupta, Auteur ; Rajiv Gupta, Auteur Année de publication : 2007 Article en page(s) : pp 473 - 484 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications
[Termes IGN] analyse multiéchelle
[Termes IGN] détection automatique
[Termes IGN] extraction de traits caractéristiques
[Termes IGN] filtre de déchatoiement
[Termes IGN] image radar moirée
[Termes IGN] transformation en ondelettesRésumé : (Auteur) This paper presents a method to despeckle Synthetic Aperture Radar (SAR) image, and then extract geographical features in it. In this research work, speckle is reduced by multiscale analysis in wavelet domain. In terms of geographical feature preservation the result shows that the method is better compared to spatial domain filters, such as Lee, Kuan, Frost, Ehfrost, Median, Gamma filters. The geographical features such as roads, airport runways, rivers and other ribbon-like shape structures are detected by the new wavelet-based method as proposed by Yuan Yan Tang. Experimental results show that the proposed method extracts geographical features of different width as well as different gray levels. Copyright ISPRS Numéro de notice : A2007-531 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.06.001 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.06.001 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28894
in ISPRS Journal of photogrammetry and remote sensing > vol 62 n° 6 (November-December 2007) . - pp 473 - 484[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-07081 SL Revue Centre de documentation Revues en salle Disponible Fusing Ikonos images by a four-band wavelet transformation method / Wei Shi in Photogrammetric Engineering & Remote Sensing, PERS, vol 73 n° 11 (November 2007)PermalinkDetermination of optimum window size for SAR image co-registration with decomposition of auto-correlation / W. Zou in Photogrammetric record, vol 22 n° 119 (September - November 2007)PermalinkWavelet based image fusion techniques: an introduction, review and comparison / Krista Amolins in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 4 (September 2007)PermalinkFeature extraction of hyperspectral images using wavelet and matching pursuit / Pai-Hui Hsu in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 2 (June 2007)PermalinkWavelet decomposition of hyperspectral data: a novel approach to quantifying pigment concentrations in vegetation / G. Blackburn in International Journal of Remote Sensing IJRS, vol 28 n°11-12 (June 2007)PermalinkIntegration of panchromatic and SAR features into multispectral spot images using the "à trous" wavelet decomposition / Y. Chibani in International Journal of Remote Sensing IJRS, vol 28 n° 10 (May 2007)PermalinkEstimation of the number of decomposition levels for a wavelet-based multiresolution multisensor image fusion / P. Pradhan in IEEE Transactions on geoscience and remote sensing, vol 44 n° 12 (December 2006)PermalinkLa transformation en ondelettes pour l'extraction de la texture-couleur : application à la classification combinée des images (HRV) de SPOT / A. Safia in International Journal of Remote Sensing IJRS, vol 27 n°18 - 19 - 20 (October 2006)PermalinkA pixel shape index coupled with spectral information for classification of high spatial resolution remotely sensed imagery / L. Zhang in IEEE Transactions on geoscience and remote sensing, vol 44 n° 10 Tome 2 (October 2006)PermalinkAdditive integration of SAR features into multispectral SPOT images by means of the à trous wavelet decomposition / Y. Chibani in ISPRS Journal of photogrammetry and remote sensing, vol 60 n° 5 (August 2006)Permalink