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Reducing edge effects in the classification of high resolution imagery / Guiyun Zhou in Photogrammetric Engineering & Remote Sensing, PERS, vol 74 n° 4 (April 2008)
[article]
Titre : Reducing edge effects in the classification of high resolution imagery Type de document : Article/Communication Auteurs : Guiyun Zhou, Auteur ; Nina S.-N. Lam, Auteur Année de publication : 2008 Article en page(s) : pp 431 - 441 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] analyse texturale
[Termes IGN] contour
[Termes IGN] fenêtre (informatique)
[Termes IGN] image à haute résolution
[Termes IGN] polygone
[Termes IGN] précision géométrique (imagerie)Résumé : (Auteur) Edge effects have been a problem in image classification especially when scale-based textural methods were included in the classification process. This paper proposes a new approach to reducing edge effects. The essence of the new approach is that all pixels in a moving window make use of the textural information instead of only the center pixel as in the traditional moving window method. The performance of the new approach was tested in three classification scenarios. The results show that the new approach generally produced higher accuracy with larger window size and was much less affected by the edge issues than the traditional moving window method. The new approach yields satisfactory results as long as the window size is smaller than the land-use polygons and the class boundaries are not too complex. Copyright ASPRS Numéro de notice : A2008-122 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.74.4.431 En ligne : https://doi.org/10.14358/PERS.74.4.431 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29117
in Photogrammetric Engineering & Remote Sensing, PERS > vol 74 n° 4 (April 2008) . - pp 431 - 441[article]Sensitivity analysis of spatially aggregated responses: a gradient-based method / F. Pantus in International journal of geographical information science IJGIS, vol 22 n° 4-5 (april 2008)
[article]
Titre : Sensitivity analysis of spatially aggregated responses: a gradient-based method Type de document : Article/Communication Auteurs : F. Pantus, Auteur ; N. Ellis, Auteur ; H. Possingham, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 575 - 599 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] agrégation spatiale
[Termes IGN] algorithme du gradient
[Termes IGN] analyse de sensibilité
[Termes IGN] données socio-économiques
[Termes IGN] espace vectoriel
[Termes IGN] noeud
[Termes IGN] polygoneRésumé : (Auteur) We often need to report on environmental, economic and social indicators, and properties at aggregated spatial scales, e.g. average income per suburb. To do this, we invariably create reporting polygons that are somewhat arbitrary. The question arises: how much does this arbitrary subdivision of space affect the outcome? In this paper, we develop a new, gradient-based framework for carrying out a rigorous analysis of the sensitivity of integrating functions to quantitative changes in their spatial configuration. This approach is applied to both analytical and empirical models, and it allows the reporting of a hierarchy of sensitivity measures (from global to local). We found that the concepts of a vector space representing the spatial configurations and the response (hyper-)surface on which gradients indicate the sensitivities to be helpful in developing the sensitivity analytical framework of spatial configurations in different dimensions. This approach works well with both analytical and empirical integrating functions. This approach resulted in a clear ranking of the sensitivities of the responses to changes in the reporting regions in an existing environmental reporting application. The approach also allowed us to find which vertices, and the directions of change of those vertices, influenced the outcome most. The application of the spatial framework allows the results to be reported in a hierarchical way, from the sensitivities of an integrative response to changes in a whole reserve/reporting system, down to the sensitivity along each of the dimensions of the vertices in the spatial configuration. The results of the spatial sensitivity framework that we developed in this paper can be readily visualized by plotting the sensitivities as vectors on geographic maps. This simplifies the presentation and facilitates the uptake of the results in the situations where the spatial configurations are complicated. Numéro de notice : A2008-155 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810701587784 En ligne : https://doi.org/10.1080/13658810701587784 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29150
in International journal of geographical information science IJGIS > vol 22 n° 4-5 (april 2008) . - pp 575 - 599[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 079-08031 RAB Revue Centre de documentation En réserve L003 Disponible 079-08032 RAB Revue Centre de documentation En réserve L003 Disponible Photogrammetric and LIDAR data integration using the centroid of a rectangular roof as a control point / Edson Aparecido Mitishita in Photogrammetric record, vol 23 n° 121 (March - May 2008)
[article]
Titre : Photogrammetric and LIDAR data integration using the centroid of a rectangular roof as a control point Type de document : Article/Communication Auteurs : Edson Aparecido Mitishita, Auteur ; A. Habib, Auteur ; J. Centeno, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 19 - 35 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] centroïde
[Termes IGN] détection de contours
[Termes IGN] données lidar
[Termes IGN] élément d'orientation externe
[Termes IGN] géoréférencement
[Termes IGN] point d'appui
[Termes IGN] reconstruction 3D du bâti
[Termes IGN] toitRésumé : (Auteur) L'intégration des données lidar avec les images photogrammétriques constitue une méthode puissante que l'on peut utiliser pour optimiser les techniques photogrammétriques en cartographie. La nature complémentaire des données photogrammétriques et lidar permet d'optimiser les performances de nombreux processus utilisés pour extraire de ces données des informations localisées et en 3D. Par exemple, l'imagerie photogrammétrique permet d'extraire avec précision les contours des bâtiments tandis que le lidar fournit avec précision des points en 3D qui nous renseignent sur la nature des surfaces de ces bâtiments. On conçoit donc l'utilité d'une combinaison de ces deux types de données pour obtenir une reconstruction plus robuste et plus complète d'objets en 3D. Les techniques photogrammétriques nécessitent de connaître les paramètres d'orientation externe des images pour en extraire les informations cartographiques. En dépit de l'existence des systèmes GPS et inertiels qui apportent une grande aide dans la géolocalisation des images, la plupart des systèmes photogrammétriques disponibles dans le commerce ont besoin d'un canevas de points d'appui pour effectuer une restitution cartographique. Etant donné les progrès réalisés ces dernières années dans la précision des systèmes lidar, on peut considérer que ces données lidar sont une source valable pour former ce canevas d'appui. Le canevas destiné à la triangulation photogrammétrique est essentiellement constitué de détails ponctuels, même si l'on utilise aussi des éléments linéaires ou surfaciques. On présente dans cet article une méthode pour géolocaliser les images photogrammétriques à partir de données lidar. Dans cette méthode on utilise les centroïdes des toits de bâtiments rectangulaires comme points d'appui photogrammétriques. Chaque centroïde issu des données lidar constitue l'un des points d'appui de ce canevas, déterminé par ses trois coordonnées et conséquent utilisable comme tel dans les systèmes photogrammétriques classiques. On a réalisé deux essais photogrammétriques pour s'assurer de la faisabilité de cette méthode. Les résultats obtenus ont confirmé qu'il était possible d'utiliser cette méthode pour géolocaliser les images photogrammétriques avec des données lidar. Copyright RS&PS + Blackwell Publishing(Auteur) L'intégration des données lidar avec les images photogrammétriques constitue une méthode puissante que l'on peut utiliser pour optimiser les techniques photogrammétriques en cartographie. La nature complémentaire des données photogrammétriques et lidar permet d'optimiser les performances de nombreux processus utilisés pour extraire de ces données des informations localisées et en 3D. Par exemple, l'imagerie photogrammétrique permet d'extraire avec précision les contours des bâtiments tandis que le lidar fournit avec précision des points en 3D qui nous renseignent sur la nature des surfaces de ces bâtiments. On conçoit donc l'utilité d'une combinaison de ces deux types de données pour obtenir une reconstruction plus robuste et plus complète d'objets en 3D. Les techniques photogrammétriques nécessitent de connaître les paramètres d'orientation externe des images pour en extraire les informations cartographiques. En dépit de l'existence des systèmes GPS et inertiels qui apportent une grande aide dans la géolocalisation des images, la plupart des systèmes photogrammétriques disponibles dans le commerce ont besoin d'un canevas de points d'appui pour effectuer une restitution cartographique. Etant donné les progrès réalisés ces dernières années dans la précision des systèmes lidar, on peut considérer que ces données lidar sont une source valable pour former ce canevas d'appui. Le canevas destiné à la triangulation photogrammétrique est essentiellement constitué de détails ponctuels, même si l'on utilise aussi des éléments linéaires ou surfaciques. On présente dans cet article une méthode pour géolocaliser les images photogrammétriques à partir de données lidar. Dans cette méthode on utilise les centroïdes des toits de bâtiments rectangulaires comme points d'appui photogrammétriques. Chaque centroïde issu des données lidar constitue l'un des points d'appui de ce canevas, déterminé par ses trois coordonnées et conséquent utilisable comme tel dans les systèmes photogrammétriques classiques. On a réalisé deux essais photogrammétriques pour s'assurer de la faisabilité de cette méthode. Les résultats obtenus ont confirmé qu'il était possible d'utiliser cette méthode pour géolocaliser les images photogrammétriques avec des données lidar. Numéro de notice : A2008-126 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/j.1477-9730.2008.00464.x En ligne : https://doi.org/10.1111/j.1477-9730.2008.00464.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29121
in Photogrammetric record > vol 23 n° 121 (March - May 2008) . - pp 19 - 35[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 106-08011 RAB Revue Centre de documentation En réserve L003 Disponible Unfolding the Earth: myriahedral projections / J. Van Wijk in Cartographic journal (the), vol 45 n° 1 (February 2008)
[article]
Titre : Unfolding the Earth: myriahedral projections Type de document : Article/Communication Auteurs : J. Van Wijk, Auteur Année de publication : 2008 Article en page(s) : pp 32 - 42 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Projections
[Termes IGN] carroyage géographique
[Termes IGN] planisphère
[Termes IGN] polyèdre
[Termes IGN] projection équivalenteRésumé : (Auteur) Myriahedral projections are a new class of methods for mapping the earth. The globe is projected on a myriahedron, a polyhedron with a very large number of faces. Next, this polyhedron is cut open and unfolded. The resulting maps have a large number of interrupts, but are (almost) conformal and conserve areas. A general approach is presented to decide where to cut the globe, followed by three different types of solution. These follow from the use of meshes based on the standard graticule, the use of recursively subdivided polyhedra and meshes derived from the geography of the earth. A number of examples are presented, including maps for tutorial purposes, optimal foldouts of Platonic solids, and a map of the coastline of the earth. Copyright British Cartographic Society Numéro de notice : A2008-132 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/000870408X276594 En ligne : https://doi.org/10.1179/000870408X276594 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29127
in Cartographic journal (the) > vol 45 n° 1 (February 2008) . - pp 32 - 42[article]Réservation
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Titre : 3D topography : a simplicial complex-based solution in a spatial DBMS Type de document : Thèse/HDR Auteurs : F. Penninga, Auteur Editeur : Delft : Netherlands Geodetic Commission NGC Année de publication : 2008 Collection : Netherlands Geodetic Commission Publications on Geodesy, ISSN 0165-1706 num. 66 Importance : 192 p. Format : 17 x 24 cm ISBN/ISSN/EAN : 978-90-6132-304-4 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique
[Termes IGN] algorithme du simplexe
[Termes IGN] base de données localisées 3D
[Termes IGN] données localisées 3D
[Termes IGN] milieu urbain
[Termes IGN] modèle conceptuel de données localisées
[Termes IGN] objet géographique 3D
[Termes IGN] système de gestion de base de données
[Termes IGN] tétraèdre
[Termes IGN] Triangulated Irregular Network
[Termes IGN] visualisation 3DIndex. décimale : 32.00 Topographie - généralités Résumé : (Auteur) Current topographic products are limited to a real world representation in only two dimensions, with at best some additional point heights and contour lines. Modelling the real world in two dimensions implies a rather drastic simplification of three di-mensional real world elements. By representing these elements in two dimensions, loss of information is inevitable. Due to this simplification, accuracy of analysis results is limited and a meaningful, insightful representation of complex situations is hard to obtain. Environmental issues like high concentrations of particulate matter along highways in urban areas, the effects of noise and odour propagation and risk analysis of liquefied petroleum gas storage tanks are random examples of current issues in 3D urban planning in which more precision is required than 2D analyses can offer. In a time with increasing attention for these kind of environmental and sustainability issues, limitations of 2D models become real problematic and trigger the demand for 3D topography.
The development of 3D topography is also supply-driven, especially by the increasing availability of high density laser scan data. Height data becomes available with point densities -multiple height points per square meter- that were previously unthinkable with traditional photogrammetric stereo techniques. Direct 3D data ac-quisition by terrestrial laser scanning is emerging, thus providing detailed measure-ments of facades, tunnels and even indoor topography. The fast developments in this field are partly triggered by the emerging popularity of personal navigation devices, which will use 3D models in the future to simplify user interpretation of the (map) display.
Objective and research question
The objective of this research is to develop a data structure that is capable of han-dling large data volumes and offers support for loading, updating, querying, analysis and especially validation. To achieve this, a triangular approach will be used, due to its advantages in maintaining consistency, its robustness and editability. This tri-angular approach creates a network of triangles (in 2D) or tetrahedrons (in 3D), in which topographic features are represented by sets of triangles or tetrahedrons. Such a network is an example of an irregular tessellation, in which the real world is de--composed into smaller (triangle/tetrahedron-shaped) building blocks. The resulting networks are called TINs (Triangular Irregular Networks) or TENs (TEtrahedronised irregular Networks). The presence of boundaries of topographic features are ensured by the use of constraints, preventing the deletion of crucial boundary edges and trian-gles. Algorithms exist to calculate these constrained triangulations and constrained tetrahedronisations of topographic data.
In this research a two-step approach will be adopted. First one has to decide how real-world objects should be modelled into features, secondly one needs to store these features in such a way that the requirements in terms of querying, analysis and validation are met. An obvious step in dealing with large volumes of geographically referenced data, is to use a spatial database.
This objective is expressed in the main research question:
How can a 3D topographic representation be realised in a feature-based triangular data model?
Note that the term 'triangular' is used here in general dimension, so both triangle-and tetrahedron-based models will be considered. As mentioned before, a two-step approach will be adopted to achieve a solution to the main research question. In accordance with the two steps, two key questions can be distinguished:
How to develop a conceptual model that describes the real world phenomena (the topographic features), regarding the general purpose-characteristic of to-pographic data sets?
How to implement this conceptual model, i.e. how to develop a suitable DBMS data structure?
The results of this research will be summarised according to this two-step approach.
A conceptual data model for 3D topography
One of the basic assumptions within this research is the use of triangular data models. As a result, topographic features will be described as sets of triangles and these fea-tures will be connected by triangles as well, thus creating one triangular network. This research explored two different approaches to triangular modelling of 3D topography.
The first one is a very pragmatic hybrid approach that combines a 2.5D* sur-face with 3D objects for those cases where 2.5D modelling is not sufficient. In terms of triangular data structures, this approach combines a TIN with several TENs. These irregular data structures not only allow varying point density (de-pending on local model complexity), but extend this irregularity into varying even model dimensionality, thus offering the ultimate fit-for-purpose approach. Unfortunately, connecting TIN and TEN networks appeared to be very difficult at design level and during prototype implementation.
The second approach avoids these problems, since it is a full 3D approach using only a TEN. Two fundamental observations are of great importance:
Physical objects have by definition a volume. In reality, there are no point, line or polygon objects; only point, line or polygon representations exist (at a certain level of abstraction/generalisation).
The real world can be considered a volume partition: a set of nonoverlap-ping volumes that form a closed (i.e. no gaps within the domain) modelled space. Objects like 'earth' or 'air' are thus explicitly included in the model.
In topographic data models, planar features like walls or roofs are obviously very useful. They can be part of the volumetric data model as 'derived features', i.e. these features depend on the relationship between volume features. For example, the earth surface is the boundary between air and earth features, while a wall or a roof are the result of adjacent building and air features. In terms of UML, these planar features are modelled as association classes. As a result, planar features are lifetime dependent from the association between two volume features.
Among the advantages of the full volumetric approach are its explicit inclusion of air and earth (often subject of analysis), its extensibility (geology, air traf-fic/telecommunication corridors, etc.) and its strong mathematical definition (full connectivity enables the use of topology for query, analysis and validation). As a re-sult, topographic features will be modelled in a TEN. Each feature will be represented by a set of tetrahedrons.
A data structure for 3D topography
The newly developed data structure has three important characteristics:
It has a solid mathematical foundation. Operators and definitions from the mathematical field of Poincare simplicial homology (part of algebraic topology) are used to handle simplexes^, the basic elements in a triangular data structure. Simplexes are well defined, ordered and constructed of simplexes of lower di-mension. The boundary operator can be used to derive these less dimensional
*See section 2.2 for an overview of often-used dimension indicators
tA simplex can loosely be defined as the simplest shape in a dimension, in which simplest refers to minimising the number of points required to define such a shape, for instance a point, a line, a triangle and a tetrahedron. See section 4.1 for a proper mathematical definition simplexes. Based on the ordering of simplexes, one can determine orientation, a useful concept in GIS. Another important concept from simplicial homology is the simplicial complex, since such a set of connected simplexes will be used to model 3D topographic features.
It is developed as a spatial database data structure. Applying definitions and operators from simplicial homology enables one to store a TEN in a relatively compact way. The new simplicial complex-based method requires only explicit storage of tetrahedrons, while simplexes of lower dimensions (triangles, edges, nodes), constraints (which guarantee feature boundary presence) and topologi-cal relationships can be derived in views. Using functions to derive views from a table is typical database functionality. In this implementation, simplexes are en-coded by their vertices, similar to the annotation in simplicial homology. These simplex encodings are extended with a feature identifier, indicating which to-pographic feature is (partly) represented by this simplex. So, a tetrahedron is encoded as 83 =< vq, Vi, V2,v^, fid >. Two variants in simplex encoding have been developed: coordinate concatenation and identifier concatenation. The concept of coordinate concatenation is to concatenate x, y and z coordinates as node identifiers and to concatenate the resulting unique node codes to describe simplexes of higher dimension. The alternative approach, identifier concatena-tion, uses separate (meaningless) node identifiers to encode simplexes to reduce the number of coordinate repetitions, since a specific node will be part of multi-ple tetrahedrons. This approach requires an additional node table to store node geometries.
It is an editable data structure, which is a crucial prerequisite to be a feasible approach for topographic data storage. Incremental updates are required, since complete rebuilds of the TEN structure will be time-consuming due to the ex-pected data volumes. Whereas most existing update algorithms for constrained tetrahedronisations use node insertions, followed by edge reconstruction, this research presents edge insertion operators. Nine exhaustive and mutually exclusive cases are distinguished, based on the location in the TEN of the inserted edge's nodes. These operators guarantee the constrained edge's presence in the structure. Existing operators might fail to recover these edges, due to the pres-ence of nearby constrained edges, which would typically happen in topographic data sets.
Conclusions
This dissertation presents a new topological approach to data modelling, based on a tetrahedral network. Operators and definitions from the field of simplicial homology are used to define and handle this structure of tetrahedrons. Simplicial homology provides a solid mathematical foundation for the data structure and offers full control over orientation of simplexes and enables one to derive substantial parts of the TEN structure efficiently, instead of explicitly storing all primitives. DBMS characteristics as the usage of views, functions and function-based indexes are extensively used to realise this potential data reduction. A proof-of-concept implementation was created and tests with several data sets show that the prevailing view that tetrahedrons are more expensive in terms of storage when compared to polyhedrons, is not correct when using the proposed approach. Storage requirements for 3D objects in tetrahe-dronised form (excluding the space in between these objects) and 3D objects stored as polyhedrons, are in the same order of magnitude.
A TEN has favourable characteristics from a computational point of view. All elements of the tetrahedral network consist by definition of flat faces, all elements are convex and they are well defined. Validation of 3D objects is also simplified by tetrahedronisation. Furthermore, a full volumetric approach enables future integra-tion of topography with other 3D data like geological layers, polluted regions or air traffic and telecommunication corridors. The price of this full volumetric approach in terms of storage space is high (about 75% of the tetrahedrons models air or earth); nevertheless this approach is likely to become justifiable due to current developments towards sustainable urban development and increased focus on environmental issues.
Now the innovative aspects of the proposed method has to be identified. Neither the idea to use a TEN data structure for 3D data nor the idea to use simplexes (in terms of simplicial homology) in a DBMS implementation is new. However, the proposed approach reduces data storage and eliminates the need for explicit updates of both topology and simplexes of lower dimension. By doing so, the approach tackles common drawbacks as TEN extensiveness and laboriousness of maintaining topology. Furthermore, applying simplicial homology offers full control over orientation of sim-plexes, which is a significant advantage, especially in 3D. In addition to this aspect, the mathematical theory of simplicial homology offers a solid theoretical foundation for both the data structure and data operations. Integrating these concepts with database functionality results in a new innovative approach to 3D data modelling.
An often raised objection to a TEN approach is its presumed complexity. Obviously, a l:n relation exists between features and their tetrahedron representations. However, as long as a user handles only features (as polyhedrons) and implemented algorithms translate these polyhedrons into operations on the TEN, one can over-come the perceived complexity. Furthermore, the prevailing view that tetrahedrons are more expensive in terms of storage than polyhedrons has been falsified in this research.
Overall, the simplicial complex-based modelling approach provides a provable correct modelling method. The use of tetrahedrons is justified by the mathematical benefits and the acceptable storage requirements. Obviously, including air and earth within the model comes at a price, but -as stated earlier- this approach is likely to become justifiable, due to current sustainability and environmentally-driven developments. The decision to develop the data structure as a database structure contributes to the overall feasibility, since a database will become indispensable due to the expected data volumes.Note de contenu : Acknowledgements
1 Introduction
1.1 Motivation
1.2 Objective and main research question
1.3 Research scope and limitations
1.4 Contribution of the work
1.5 Outline
2 Research background
2.1 Problem domain: Towards 3D topography
2.2 Defining dimensions in the range 2D-3D
2.3 Deriving requirements for the conceptual data model and structure from the problem
2.4 Managing 3D data: related research on 3D data structures
2.5 Triangular data structures and algorithms
2.6 Relevant database concepts
I Conceptual modelling of 3D Topography
3 Two triangular data models for 3D topography
3.1 Approach 1: an integrated 2.5D/3D model
3.2 Approach 2: a full 3D data model
3.3 The choice for the full 3D approach
II A Data structure for 3D Topography
4 Theoretical foundations: Poincare simplicial homology
4.1 Mathematical description of simplexes
4.2 Orientation of simplexes
4.3 Combining simplexes: simplicial complexes
4.4 Operations on simplexes and simplicial complexes
5 A simplicial complex-based solution for 3D topography
5.1 Representing topographic features in a TEN
5.2 Early ideas: three TEN-based data structures for the full 3D approach
5.3 Preferred solution: applying simplicial homology to the TEN
5.4 Implementing the data structure in a DBMS environment
5.5 Summary
6 Updating features in the Data Structure
6.1 Incremental update: feature insertion
6.2 Incremental update: feature deletion
6.3 Quality improvement of TEN structure
6.4 Initial bulk loading and bulk rebuild
III Evaluation and conclusions
7 Evaluation and discussion
7.1 Evaluation material: three different data sets
7.2 Evaluating bulk tetrahedronisation process
7.3 Evaluating storage requirements
7.4 Evaluating initial visualisation tools
7.5 Discussing requirements for 3D data sets with correct topology
7.6 Identifying future developments
8 Conclusions
8.1 Results.
8.2 Main conclusions
8.3 Discussion
8.4 Future researchNuméro de notice : 15361 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Thèse étrangère DOI : sans En ligne : https://www.ncgeo.nl/index.php/en/publicatiesgb/publications-on-geodesy/item/250 [...] Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=62703 Réservation
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Code-barres Cote Support Localisation Section Disponibilité 15361-01 32.00 Livre Centre de documentation Topographie Disponible 15361-02 32.00 Livre Centre de documentation Topographie Disponible PermalinkPermalinkRoadmark reconstruction from stereo-images acquired by a ground-based mobile mapping system / Bahman Soheilian (2008)PermalinkPermalinkAn unbiased algorithm for detection of curvilinear structures in urban remote sensing images / Jinzheng Peng in International Journal of Remote Sensing IJRS, vol 28 n°23-24 (December 2007)PermalinkMeasuring land development in urban regions using graph theoretical and conditional statistical features / C. Unsalan in IEEE Transactions on geoscience and remote sensing, vol 45 n° 12 Tome 1 (December 2007)PermalinkClassified road detection from satellite images based on perceptual organization / J. 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Tsai in International journal of geographical information science IJGIS, vol 21 n° 9-10 (october 2007)PermalinkAutomatic extraction of main road centrelines from high resolution satellite imagery using hierarchical grouping / Xiangyun Hu in Photogrammetric Engineering & Remote Sensing, PERS, vol 73 n° 9 (September 2007)PermalinkCaractérisation fractale du relief du Lodévois après extraction de tendances topographiques générales / Pascal Martin in Revue internationale de géomatique, vol 17 n° 3-4 (septembre 2007 – février 2008)PermalinkCalli-info-carto-graphie / Anonyme in Géomatique expert, n° 57 (01/07/2007)PermalinkData fusion of high-resolution satellite imagery and Lidar data for automatic building extraction / Gunho Sohn in ISPRS Journal of photogrammetry and remote sensing, vol 62 n° 1 (May 2007)PermalinkDetection and vectorization of roads from lidar data / S. 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