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A region-based level set segmentation for automatic detection of man-made objects from aerial and satellite Images / K. Karatzalos in Photogrammetric Engineering & Remote Sensing, PERS, vol 75 n° 6 (June 2009)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 75 n° 6 (June 2009) . - pp 667 - 677 Titre : A region-based level set segmentation for automatic detection of man-made objects from aerial and satellite Images Type de document : Article/Communication Auteurs : K. Karatzalos, Auteur ; Demetre Argialas, Auteur Année de publication : 2009 Article en page(s) : pp 667 - 677 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] détail topographique artificiel [Termes IGN] détection du bâti [Termes IGN] extraction automatique [Termes IGN] image aérienne [Termes IGN] image satellite [Termes IGN] segmentation d'image [Termes IGN] traitement géométrique de données Résumé : (Auteur) A region-based level set segmentation was developed for the automatic detection of man-made objects from aerial and satellite images. The essence of the approach is to optimize the position and the geometric form of an evolving curve, by measuring information within the regions that compose a particular image partition based on their statistical description. The present region-based variational model is fully automated without the need to manually specify the position of the initial contour. Furthermore, it converges after a small number of iterations, allowing real-time applications. The developed algorithm was tested for the detection of roads, buildings and other man-made objects in a number of aerial and satellite images. The effectiveness of the algorithm is demonstrated by the experimental results and the performed qualitative and quantitative. Numéro de notice : A2009-259 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.75.6.667 En ligne : https://doi.org/10.14358/PERS.75.6.667 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29889 [article]

An adaptive thresholding multiple classifiers system for remote sensing image classification / Y. Tzeng in Photogrammetric Engineering & Remote Sensing, PERS, vol 75 n° 6 (June 2009)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 75 n° 6 (June 2009) . - pp 679 - 687 Titre : An adaptive thresholding multiple classifiers system for remote sensing image classification Type de document : Article/Communication Auteurs : Y. Tzeng, Auteur ; K. Fan, Auteur ; K.S. Chen, Auteur Année de publication : 2009 Article en page(s) : pp 679 - 687 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte [Termes IGN] classificateur [Termes IGN] classification automatique [Termes IGN] classification hybride [Termes IGN] ensachage [Termes IGN] image optique [Termes IGN] image radar [Termes IGN] seuillage d'image Résumé : (Auteur) A multiple classifiers system which adopts an effective weighting policy to combine the output of several classifiers, generally leads to a better performance in image classification. The two most commonly used weighting policies are Bagging and Boosting algorithms. However, their performance is limited by high levels of ambiguity among classes. To overcome this difficulty, an adaptive thresholding criterion was proposed. By applying it to SAR and optical images for terrain cover classification, comparisons between the multiple classifiers systems using the Bagging and/or Boosting algorithms with and without the adaptive thresholding criterion were made. Experimental results showed that the classification substantially improved when the adaptive thresholding criterion was used, especially when the level of ambiguity of targets was high. Copyright ASPRS Numéro de notice : A2009-260 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.75.6.679 En ligne : https://doi.org/10.14358/PERS.75.6.679 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29890 [article]

Radiometric normalization of SPOT-5 scenes: 6S Atmospheric Model versus Pseudo-invariant Features / A. Davranche in Photogrammetric Engineering & Remote Sensing, PERS, vol 75 n° 6 (June 2009)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 75 n° 6 (June 2009) . - pp 723 - 728 Titre : Radiometric normalization of SPOT-5 scenes: 6S Atmospheric Model versus Pseudo-invariant Features Type de document : Article/Communication Auteurs : A. Davranche, Auteur ; G. Lefebvre, Auteur ; B. Poulin, Auteur Année de publication : 2009 Article en page(s) : pp 723 - 728 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse diachronique [Termes IGN] Camargue [Termes IGN] correction radiométrique [Termes IGN] détection de changement [Termes IGN] image SPOT 5 [Termes IGN] modèle atmosphérique [Termes IGN] objet géographique Résumé : (Auteur) We compared the efficiency and robustness of two radiometric correction techniques applied to six SPOT-5 scenes used for assessing environmental changes of Camargue wetlands: the 6S atmospheric model and 86 pseudo-invariant features (PIFs) found in deep water, pine trees, roofs and sand. The few PIFs were selected subjectively following the low number of potentially invariant sectors available on the scenes. Both approaches provided a similar radiometric variation (6S = 4.3 percent; PIFs = 4.0 percent). The latter increased from water to pine trees, to roofs and sand, with five reference points per feature being identified as cost effective. The withdrawing of variant features among the PIFs across dates or points caused a significant decrease in radiometric variation, especially with 6S (6S = 2.8 percent, PIFs = 3.4 percent). As many as 31 point per type of PIFs would be necessary to provide a radiometric variation that is not significantly different from that obtained with 6S, whereas nearly 300 and 4,000 points per feature would be required to provide similar or better results than the 6S code, respectively. Use of a few PIFs remains a valid approach, as long as the invariant sectors cover a wide range of brightness and are represented by objects of which the radiometric variation has preliminarily been tested. Copyright ASPRS Numéro de notice : A2009-261 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.75.6.723 En ligne : https://doi.org/10.14358/PERS.75.6.723 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29891 [article]

Occlusion-based methodology for the classification of Lidar Data / A.F. Habib in Photogrammetric Engineering & Remote Sensing, PERS, vol 75 n° 6 (June 2009)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 75 n° 6 (June 2009) . - pp 703 - 712 Titre : Occlusion-based methodology for the classification of Lidar Data Type de document : Article/Communication Auteurs : A.F. Habib, Auteur ; Y. Chang, Auteur ; D.C. Lee, Auteur Année de publication : 2009 Article en page(s) : pp 703 - 712 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] angle nadiral [Termes IGN] changement d'utilisation du sol [Termes IGN] détection d'objet [Termes IGN] détection de partie cachée [Termes IGN] données lidar [Termes IGN] extraction automatique [Termes IGN] filtrage statistique [Termes IGN] interpolation [Termes IGN] lasergrammétrie [Termes IGN] modèle numérique de surface [Termes IGN] relief [Termes IGN] semis de points Résumé : (Auteur) Lidar systems have been widely adopted for the acquisition of dense and accurate topographic data over extended areas. The level of detail and the quality of the collected point cloud motivated the research community to investigate the possibility of automatic object extraction from such data. Prior knowledge of the terrain surface will improve the performance of object detection and extraction procedures. In this paper, a new strategy for automatic terrain extraction from lidar data is presented. The proposed strategy is based on the fact that sudden elevation changes, which usually correspond to non-ground objects, will cause relief displacements in perspective views. The introduced relief displacements will occlude neighboring ground points. To start the process, we generate a digital surface model (DSM) from the irregular lidar points using an interpolation procedure. The presence of sudden-elevation changes and the resulting occlusions can be discerned by sequentially checking the off-nadir angles to the lines of sight connecting the DSM cells and a pre-defined set of synthesized projection centers. Detected occlusions are then used to identify the occluding points, which are hypothesized to be non-ground points. Surface roughness and discontinuities together with inherent noise in the point cloud will lead to some false hypotheses. Therefore, we use a statistical filter to remove these false hypotheses. The performance of the algorithm has been evaluated and verified using both simulated and real lidar datasets with varying levels of complexity. Copyright ASPRS Numéro de notice : A2009-262 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.75.6.703 En ligne : https://doi.org/10.14358/PERS.75.6.703 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29892 [article]