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A two-step displacement correction algorithm for registration of lidar point clouds and aerial images without orientation parameters / H. Wu in Photogrammetric Engineering & Remote Sensing, PERS, vol 76 n° 10 (October 2010)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 76 n° 10 (October 2010) . - pp 1135 - 1145 Titre : A two-step displacement correction algorithm for registration of lidar point clouds and aerial images without orientation parameters Type de document : Article/Communication Auteurs : H. Wu, Auteur ; Y. Li, Auteur ; J. Li, Auteur ; J. Gong, Auteur Année de publication : 2010 Article en page(s) : pp 1135 - 1145 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] données lidar [Termes IGN] élément d'orientation externe [Termes IGN] fusion de données [Termes IGN] image aérienne [Termes IGN] modèle linéaire [Termes IGN] semis de points [Termes IGN] superposition d'images [Termes IGN] superposition de données [Termes IGN] zone urbaine Résumé : (Auteur) This paper presents a novel linear registration algorithm for lidar point clouds and aerial images without orientation parameters. First, preprocessing is conducted to classify the lidar point clouds into ground points, building points, and aboveground, non-building points. After preprocessing, the algorithm consists of two sequential steps, i.e., Tilt Displacement Correction and Height Displacement Correction. As the kernel of the proposed registration algorithm, the mathematical model for Height Displacement Correction is a set of linear formulas analytically deduced from the rigorous geometric function of a single image. The proposed registration algorithm does not require any orientation parameters for the image, which greatly lowers the requirements for image acquisition. Due to the model's linearity, the proposed algorithm is computationally efficient. Our experimental results demonstrate that the proposed algorithm can register aerial images without orientation parameters at the same accuracy level of space resection based on collinear equations. This result fulfills the requirement for the fusion of lidar range data and aerial images in most large-scale urban modeling applications. Numéro de notice : A2010-431 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.76.10.1135 En ligne : https://doi.org/10.14358/PERS.76.10.1135 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30624 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
105-2010101	RAB	Revue	Centre de documentation	En réserve L003	Disponible
105-2010102	RAB	Revue	Centre de documentation	En réserve L003	Disponible

A partition-based serial algorithm for generating viewshed on massive DEMs / H. Wu in International journal of geographical information science IJGIS, vol 21 n° 9-10 (october 2007)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 21 n° 9-10 (october 2007) . - pp 955 - 964 Titre : A partition-based serial algorithm for generating viewshed on massive DEMs Type de document : Article/Communication Auteurs : H. Wu, Auteur ; M. Pan, Auteur ; L. Yao, Auteur ; B. Luo, Auteur Année de publication : 2007 Article en page(s) : pp 955 - 964 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] algorithme géométrique [Termes IGN] modèle numérique de surface [Termes IGN] partitionnement par bloc Résumé : (Auteur) As increasingly large-scale and higher-resolution terrain data have become available, for example air-form and space-borne sensors, the volume of these datasets reveals scalability problems with existing GIS algorithms. To address this problem, a kind of serial algorithm was developed to generate viewshed on large grid-based digital elevation models (DEMs). We first divided the whole DEM into rectangular blocks in row and column directions (called block partitioning), then processed these blocks with four axes followed by four sectors sequentially. When processing the particular block, we adopted the 'reference plane' algorithm to calculate the visibility of the target point on the block, and adjusted the calculation sequence according to the different spatial relationships between the block and the viewpoint since the viewpoint is not always inside the DEM. By adopting the 'Reference Plane' algorithm and using a block partitioning method to segment and load the DEM dynamically, it is possible to generate viewshed efficiently in PC-based environments. Experiments showed that the divided block should be dynamically loaded whole into computer main memory when partitioning, and the suggested approach retains the accuracy of the reference plane algorithm and has near linear compute complexity. Copyright Taylor & Francis Numéro de notice : A2007-551 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/13658810601034218 En ligne : https://doi.org/10.1080/13658810601034218 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28914 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-07061	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-07062	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Structured approach to implementing automatic cartographic generalization / H. Wu (23/06/1997)

Public contenu dans ICC 97 proceedings 18th ICA/ACI International Cartographic Conference, 1. Volume 1 / L. Ottoson (1997) Titre : Structured approach to implementing automatic cartographic generalization Type de document : Article/Communication Auteurs : H. Wu, Auteur Editeur : Gävle : Swedish Cartographic Society Année de publication : 23/06/1997 Conférence : ICC 1997, 18th international cartographic conference ICA 23/06/1997 27/06/1997 Stockholm Suède OA Proceedings Importance : pp 349 - 356 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] diagramme de Voronoï [Termes IGN] généralisation cartographique automatisée [Termes IGN] géomètrie algorithmique [Termes IGN] géométrie fractale [Termes IGN] réseau hydrographique [Termes IGN] théorie des graphes [Vedettes matières IGN] Généralisation Résumé : (Auteur) Taking the generalization of river network, relief forms and grouped point objects as examples, in this paper a new complete theory system for structured cartographic generalization is founded on the graph theory, fractal and computational geometry, and a logical operation sequence is established. Numéro de notice : C1997-063 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Communication Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=65722