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Variable-resolution compression of vector data / B. Yang in Geoinformatica, vol 12 n° 3 (September - November 2008)  

Public [article]  inGeoinformatica > vol 12 n° 3 (September - November 2008) . - pp 357 - 376 Titre : Variable-resolution compression of vector data Type de document : Article/Communication Auteurs : B. Yang, Auteur ; Ross S. Purves, Auteur ; Robert Weibel, Auteur Année de publication : 2008 Article en page(s) : pp 357 - 376 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] arc [Termes IGN] compression de données [Termes IGN] données vectorielles [Termes IGN] élimination de points [Termes IGN] noeud [Termes IGN] objet géographique [Termes IGN] résolution multiple Résumé : (Auteur) The compression of spatial data is a promising solution to reduce the space of data storage and to decrease the transmission time of spatial data over the Internet. This paper proposes a new method for variable-resolution compression of vector data. Three key steps are encompassed in the proposed method, namely, the simplification of vector data via the elimination of vertices, the compression of removed vertices, and the decoding of the compressed vector data. The proposed compression method was implemented and applied to compress vector data to investigate its performance in terms of the compression ratio, distortions of geometric shapes. The results show that the proposed method provides a feasible and efficient solution for the compression of vector data, is able to achieve good compression ratios and maintains the main shape characteristics of the spatial objects within the compressed vector data. Copyright Springer Numéro de notice : A2008-284 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-007-0036-x En ligne : https://doi.org/10.1007/s10707-007-0036-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29277 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-08031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Cartographic line generalization with waterlines and medial-axes / A.H.J. Christensen in Cartography and Geographic Information Science, vol 26 n° 1 (January 1999)  

Public [article]  inCartography and Geographic Information Science > vol 26 n° 1 (January 1999) . - pp 19 - 32 Titre : Cartographic line generalization with waterlines and medial-axes Type de document : Article/Communication Auteurs : A.H.J. Christensen, Auteur Année de publication : 1999 Article en page(s) : pp 19 - 32 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] agrégation de détails [Termes IGN] élimination de points [Termes IGN] généralisation cartographique automatisée [Termes IGN] lissage de courbe [Termes IGN] objet géographique linéaire [Termes IGN] trait de côte [Vedettes matières IGN] Généralisation Résumé : (Auteur) A line generalization solution is presented based on the operations known as waterlining and medialaxis transformation. Although the solution is of general application, this report focuses on shorelines. The method is shown to preserve the general shape of a line through very broad scale changes ; it also makes it possible to perform feature aggregation and elimination, where needed. Each scale change is proven to depend on the maximum distance spanned by the waterlining operation, which distance can be equated to the quantity known as in the generalization literature. The challenges encountered in the development of the generalization procedure are discussed ; these challenges are less on the side of line simplification and more in the aggregation of features. Solutions are presented for broadening isthmus, linkages to streams and rivers, and the collapsing of straits into double and coincident lines. Particular shoreline configurations are shown to lead to ambiguities in feature aggregation and elimination that require user's input in order to be resolved. Intermediate results are found to replicate those submitted 39 years ago by Julian Perkal in his proposal for an objective generalization. Numéro de notice : A1999-169 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304099782424893 En ligne : https://www.tandfonline.com/doi/abs/10.1559/152304099782424893 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26367 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
032-99011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Line generalisation by repeated elimination of points / M. Visvalingam in Cartographic journal (the), vol 30 n° 1 (June 1993)  

Public [article]  inCartographic journal (the) > vol 30 n° 1 (June 1993) . - pp 46 - 51 Titre : Line generalisation by repeated elimination of points Type de document : Article/Communication Auteurs : M. Visvalingam, Auteur ; J.D. Whyatt, Auteur Année de publication : 1993 Article en page(s) : pp 46 - 51 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] algorithme de Douglas-Peucker [Termes IGN] élimination de points [Termes IGN] généralisation cartographique automatisée [Termes IGN] lissage de courbe [Termes IGN] objet géographique linéaire [Vedettes matières IGN] Généralisation Résumé : (Auteur) This paper presents a new approach to line generalisation which uses the concept of 'effective area' for progressive simplification of a line by point elimination. Two coastlines are used to compare the performance of this, with that of the widely used Douglas-Peucker, algorithm. The results from the areabased algorithm compare favourably with manual generalisation of the same lines. It is capable of achieving both imperceptible minimal simplifications and caricatural generalisations. By careful selection of cut-off values, it is possible to use the same algorithm for scaledependent and scaleindependent generalisations. More importantly, it offers scope for modelling cartographic lines as consisting of features within features so that their geometric manipulation may be modified by application- -and/ or userdefined rules and weights. The paper examines the merits and limitations of the algorithm and the opportunities it offers for further research and progress in the field of line generalisation. Numéro de notice : A1993-027 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/000870493786962263 En ligne : https://www.tandfonline.com/doi/abs/10.1179/000870493786962263 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25693 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
030-93011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Some observation on the issue of line generalisation / Z. Li in Cartographic journal (the), vol 30 n° 1 (June 1993)  

Public [article]  inCartographic journal (the) > vol 30 n° 1 (June 1993) . - pp 68 - 71 Titre : Some observation on the issue of line generalisation Type de document : Article/Communication Auteurs : Z. Li, Auteur Année de publication : 1993 Article en page(s) : pp 68 - 71 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] élimination de points [Termes IGN] généralisation cartographique automatisée [Termes IGN] lissage de courbe [Termes IGN] objet géographique linéaire [Termes IGN] réduction [Vedettes matières IGN] Généralisation Résumé : (Auteur) This short article addresses some of the problems in cartographic generalisation, especially the misuse of data point reduction algorithms for generalisation purpose. Special attention is paid to line generalisation. Through analysis, the author emphasizes that 'data reduction' is applied when the scale change is not of concern, while generalisation is applied due to the change in scales. Therefore, data point reduction algorithms should not be used for generalisation purposes. Also different benchmarks such as the manually generalised versions of existing maps should be used for the purpose of evaluating line generalisation algorithms instead of always using the original feature. Numéro de notice : A1993-028 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/000870493786962191 En ligne : https://www.tandfonline.com/doi/abs/10.1179/000870493786962191 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25694 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
030-93011	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Area-patch generalisation: a competitive approach / Jean-Claude Müller in Cartographic journal (the), vol 29 n° 2 (December 1992)  

Public [article]  inCartographic journal (the) > vol 29 n° 2 (December 1992) . - pp 137 - 144 Titre : Area-patch generalisation: a competitive approach Type de document : Article/Communication Auteurs : Jean-Claude Müller, Auteur ; W. Zeshen, Auteur Année de publication : 1992 Article en page(s) : pp 137 - 144 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] agrégation de données [Termes IGN] élimination de points [Termes IGN] généralisation cartographique automatisée [Termes IGN] intégrité topologique [Termes IGN] lissage de données [Termes IGN] objet géographique zonal [Vedettes matières IGN] Généralisation Résumé : (Auteur) A solution to the automated generalisation of one particular class of geographical objects is proposed. Those objects are area patches distributed over a two-dimensional space. They are assumed to be semantically identical ; hence the competition for space occurs on the basis of geometric considerations only. The solution proposed is algorithmic, stepwise and works for vector data only. The steps include data preprocessing, area expansion and contraction, elimination, reselection, aggregation, displacement, integrity check, smoothing and reduction. Among the generalisation rules which were applied are : (1) emphasis on larger patches at the expense of smaller ones, (2) preservation of the overall figure/group relationship, (3) partial topological integrity, and (4) differential displacement according to patch area. Results are discussed within the wider framework of topographic map generalisation where diversified objects must be simultaneously generalised. Numéro de notice : A1992-016 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/000870492787859763 En ligne : https://www.tandfonline.com/doi/abs/10.1179/000870492787859763 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=25667 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
030-92021	RAB	Revue	Centre de documentation	En réserve L003	Disponible