Centre dedocumentation
scientifique

Regression modeling of reduction in spatial accuracy and detail for multiple geometric line simplification procedures / Timofey Samsonov in International journal of cartography, Vol 6 n° 1 (March 2020)  

Public [article]  inInternational journal of cartography > Vol 6 n° 1 (March 2020) . - pp 47 - 70 Titre : Regression modeling of reduction in spatial accuracy and detail for multiple geometric line simplification procedures Type de document : Article/Communication Auteurs : Timofey Samsonov, Auteur ; Olga P. Yakimova, Auteur Année de publication : 2020 Article en page(s) : pp 47 - 70 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] algorithme de Douglas-Peucker [Termes descripteurs IGN] algorithme de Visvalingam [Termes descripteurs IGN] modèle de régression [Termes descripteurs IGN] niveau de détail [Termes descripteurs IGN] précision cartographique [Termes descripteurs IGN] représentation des détails topographiques [Termes descripteurs IGN] simplification de contour [Vedettes matières IGN] Généralisation Résumé : (auteur) One of the important stages of map generalization is the selection of optimal simplification procedure for each spatial feature or feature type. Selected algorithms are then applied collaboratively to simplify the whole set of features. However, there is a lack of investigations that report a systematic approach of deriving a similar reduction in accuracy and detail by using different algorithms. In current paper we propose the solution to this problem on the basis of regression modeling between tolerance value of each algorithm and the value of some geometric measure which describes changes in accuracy and detail of the line. This allows fitting the regression model between tolerance values of the two selected algorithms which can be used to obtain similar simplification results. Regressions between Douglas-Peucker, Li-Openshaw and Visvalingam-Whyatt algorithm tolerance values are investigated. Application of methodology is illustrated on the example of three coastlines with significantly different spatial character. Results of the study show that regression coefficients depend highly both on the combination of the two algorithms, and on the character of the line. Finally, it is shown that a weighted combination of accuracy and detail regression models can be used to model the changes in level of detail of the line. Numéro de notice : A2020-071 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/23729333.2019.1615745 date de publication en ligne : 29/07/2019 En ligne : https://doi.org/10.1080/23729333.2019.1615745 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94634 [article]

Variable DEM generalization using local entropy for terrain representation through scale / Paulo Raposo in International journal of cartography, Vol 6 n° 1 (March 2020)  

Public [article]  inInternational journal of cartography > Vol 6 n° 1 (March 2020) . - pp 99 - 120 Titre : Variable DEM generalization using local entropy for terrain representation through scale Type de document : Article/Communication Auteurs : Paulo Raposo, Auteur Année de publication : 2020 Article en page(s) : pp 99 - 120 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] courbe de niveau [Termes descripteurs IGN] entropie [Termes descripteurs IGN] filtre passe-bas [Termes descripteurs IGN] généralisation cartographique [Termes descripteurs IGN] lissage de valeur [Termes descripteurs IGN] modèle numérique de surface [Termes descripteurs IGN] représentation multiple [Termes descripteurs IGN] voisinage (topologie) [Vedettes matières IGN] Généralisation Résumé : (auteur) An automated method of variable digital elevation model (DEM) smoothing is presented. Using variably sized kernels to perform filtering, the method is driven by the entropy of local z-values in the DEM, i.e. the amount of information necessary to convey the elevation variety in the neighborhood of each pixel. This paper presents the method in service of low-pass filtering in order to smooth the raster, though other neighborhood-based filters could be implemented as well. When used in smoothing, the method successfully retains detail in areas of higher relief variation and suppresses it in areas of lower variation, thereby retaining more salient features like ridges, peaks, or incised valleys, while diminishing flatter ones. Varying the neighborhood size with which entropy calculations are made allows for filtering through continuous map scale, enabling multi-scale representation. The method also includes a simple correction for smoothed pixels such that their z-value range reflects that of the input DEM, thereby ensuring that subsequent products such as generated contour lines remain within correct ranges. Several illustrations are given of the method's results. Numéro de notice : A2020-072 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/23729333.2019.1687973 date de publication en ligne : 16/12/2019 En ligne : https://doi.org/10.1080/23729333.2019.1687973 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94636 [article]

Camera orientation, calibration and inverse perspective with uncertainties: a Bayesian method applied to area estimation from diverse photographs / Grégoire Guillet in ISPRS Journal of photogrammetry and remote sensing, vol 159 (January 2020)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 159 (January 2020) . - pp 237 - 255 Titre : Camera orientation, calibration and inverse perspective with uncertainties: a Bayesian method applied to area estimation from diverse photographs Type de document : Article/Communication Auteurs : Grégoire Guillet, Auteur ; Thomas Guillet, Auteur ; Ludovic Ravanel, Auteur Année de publication : 2020 Article en page(s) : pp 237 - 255 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes descripteurs IGN] ajustement de paramètres [Termes descripteurs IGN] appariement d'images [Termes descripteurs IGN] autocorrélation spatiale [Termes descripteurs IGN] distorsion d'image [Termes descripteurs IGN] estimation bayesienne [Termes descripteurs IGN] étalonnage de chambre métrique [Termes descripteurs IGN] figuration de la densité [Termes descripteurs IGN] fonction inverse [Termes descripteurs IGN] image 2D [Termes descripteurs IGN] image aérienne [Termes descripteurs IGN] incertitude géométrique [Termes descripteurs IGN] longueur focale [Termes descripteurs IGN] méthode de Monte-Carlo par chaînes de Markov [Termes descripteurs IGN] modèle numérique de surface [Termes descripteurs IGN] orientation externe [Termes descripteurs IGN] photographie numérique [Termes descripteurs IGN] vue 3D [Termes descripteurs IGN] vue perspective Résumé : (Auteur) Large collections of images have become readily available through modern digital catalogs, from sources as diverse as historical photographs, aerial surveys, or user-contributed pictures. Exploiting the quantitative information present in such wide-ranging collections can greatly benefit studies that follow the evolution of landscape features over decades, such as measuring areas of glaciers to study their shrinking under climate change. However, many available images were taken with low-quality lenses and unknown camera parameters. Useful quantitative data may still be extracted, but it becomes important to both account for imperfect optics, and estimate the uncertainty of the derived quantities. In this paper, we present a method to address both these goals, and apply it to the estimation of the area of a landscape feature traced as a polygon on the image of interest. The technique is based on a Bayesian formulation of the camera calibration problem. First, the probability density function (PDF) of the unknown camera parameters is determined for the image, based on matches between 2D (image) and 3D (world) points together with any available prior information. In a second step, the posterior distribution of the feature area of interest is derived from the PDF of camera parameters. In this step, we also model systematic errors arising in the polygon tracing process, as well as uncertainties in the digital elevation model. The resulting area PDF therefore accounts for most sources of uncertainty. We present validation experiments, and show that the model produces accurate and consistent results. We also demonstrate that in some cases, accounting for optical lens distortions is crucial for accurate area determination with consumer-grade lenses. The technique can be applied to many other types of quantitative features to be extracted from photographs when careful error estimation is important. Numéro de notice : A2020-015 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2019.11.013 date de publication en ligne : 02/12/2019 En ligne : https://doi.org/10.1016/j.isprsjprs.2019.11.013 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94404 [article]

Réservation

Réserver ce document

Exemplaires (3)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
081-2020011	SL	Revue	Centre de documentation	Revues en salle	Disponible
081-2020013	DEP-RECP	Revue	MATIS	Dépôt en unité	Exclu du prêt
081-2020012	DEP-RECF	Revue	Nancy	Dépôt en unité	Exclu du prêt

Bertin’s graphic variables and online map makers: an empirical study of maps produced by prosumers and cartographers / Natalia Ipatow in Cartographica, vol 54 n° 4 (Winter 2019)  

Public [article]  inCartographica > vol 54 n° 4 (Winter 2019) . - pp 233 - 244 Titre : Bertin’s graphic variables and online map makers: an empirical study of maps produced by prosumers and cartographers Type de document : Article/Communication Auteurs : Natalia Ipatow, Auteur ; Francis Harvey, Auteur Année de publication : 2019 Article en page(s) : pp 233 - 244 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie numérique [Termes descripteurs IGN] approche participative [Termes descripteurs IGN] cartographe [Termes descripteurs IGN] communication cartographique [Termes descripteurs IGN] conception cartographique [Termes descripteurs IGN] enquête [Termes descripteurs IGN] information cartographique [Termes descripteurs IGN] information sémantique [Termes descripteurs IGN] représentation graphique [Termes descripteurs IGN] sémiologie graphique [Termes descripteurs IGN] visualisation de données [Termes descripteurs IGN] web mapping Résumé : (Auteur) Near-ubiquitous Internet access with widely available user-friendly Web tools and software packages for map creation have allowed an increasing number of digitally savvy map makers, including prosumers, to communicate with other people using mashup maps for some years. This article presents an empirical study that looks at the question of how prosumers and cartographers use the graphical variables developed by Jacques Bertin in 1967 for cartographic communication. The findings suggest that both prosumers and trained cartographers mainly use the graphical variables colour hue and shape. Trained cartographers additionally use the graphical variables size and colour value to represent ordinal, nominal, and numerical data. The persistence of this difference speaks to the continued importance of cartographic training for effective cartographic communication. Numéro de notice : A2019-558 Thématique : GEOMATIQUE Nature : Article DOI : 10.3138/cart.54.4.2018-0024 date de publication en ligne : 05/12/2019 En ligne : https://doi.org/10.3138/cart.54.4.2018-0024 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=94351 [article]

Réservation

Réserver ce document

Exemplaires (2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
031-2019041	SL	Revue	Centre de documentation	Revues en salle	Disponible
031-2019042	SL	Revue	Centre de documentation	Revues en salle	Disponible

Empirical studies on the visual perception of spatial patterns in choropleth maps / Jochen Schiewe in KN, Journal of Cartography and Geographic Information, vol 69 n° 3 (September 2019)  

Public [article]  inKN, Journal of Cartography and Geographic Information > vol 69 n° 3 (September 2019) . - pp 217 - 228 Titre : Empirical studies on the visual perception of spatial patterns in choropleth maps Type de document : Article/Communication Auteurs : Jochen Schiewe, Auteur Année de publication : 2019 Article en page(s) : pp 217 - 228 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] analyse de données [Termes descripteurs IGN] carte choroplèthe [Termes descripteurs IGN] couleur (rédaction cartographique) [Termes descripteurs IGN] enquête [Termes descripteurs IGN] erreur systématique [Termes descripteurs IGN] rédaction cartographique [Termes descripteurs IGN] vision [Vedettes matières IGN] Cartologie Résumé : (Auteur) An essential purpose of choropleth maps is the visual perception of spatial patterns (such as the detection of hot spots or extreme values). This requires an effective and as intuitive as possible comparison of color values between different regions. Accordingly, a number of design requirements must be considered. Due to the lack of empirical evidence regarding some elementary design aspects, an online study with 260 participants was conducted. Three closely related effects were examined: the “dark-is-more bias” (i.e., the intuitive ranking of color lightness), the “area-size bias” (i.e., the neglect of small areas, since these are less dominant in perception than larger ones) and the “data-classification effect” (i.e., attention to data classification when interpreting spatial patterns). For each hypothesis, one or more maps in connection with single or multiple choice questions were presented. Users should detect extreme values, central tendencies or homogeneities of values as well as comment on their task solving certainty. In general, the hypotheses regarding the mentioned effects could be confirmed by statistical analysis. The results are used to derive conclusions and topics for future research. In particular, further comparative empirical studies are recommended to determine the best possible map types for given applications, also considering alternatives to choropleth maps. Numéro de notice : A2019-459 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s42489-019-00026-y date de publication en ligne : 13/08/2019 En ligne : https://doi.org/10.1007/s42489-019-00026-y Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93550 [article]

“Mapping-with”: The Politics of (Counter-)classification in OpenStreetMap / Clancy Wilmott in Cartographic perspectives, n°92 (2019)  

Permalink

Graphically supported evaluation of mapping techniques used in presenting spatial accessibility / Lukasz Wielebski in Cartography and Geographic Information Science, Vol 46 n° 4 (July 2019)  

Permalink

Cartographic symbol design considerations for the space–time cube / Christopher League in Cartographic journal (the), Vol 56 n° 2 (May 2019)  

Permalink

Champs et objets pour mieux représenter les phénomènes dans leur contexte géographique / Anne Ruas in Revue internationale de géomatique, vol 29 n° 2 (avril - juin 2019)  

Permalink

n° 94 - Avril 2019 - Cartographie 4.0 : naviguer avec les cartes du XXIème siècle (Bulletin de Responsabilité et environnement) / Françoise Roure    

Permalink

Building detection and regularisation using DSM and imagery information / Yousif A. Mousa in Photogrammetric record, vol 34 n° 165 (March 2019)  

Permalink

Geographic space as a living structure for predicting human activities using big data / Bin Jiang in International journal of geographical information science IJGIS, Vol 33 n° 3-4 (March - April 2019)  

Permalink

A virtual globe using a discrete global grid system to illustrate the modifiable areal unit problem / Paulo Raposo in Cartographica, vol 54 n° 1 (spring 2019)  

Permalink

Smart cartographic background symbolization for map mashups in geoportals : A proof of concept by example of landuse representation / Nadia H. Panchaud in Cartographic journal (the), Vol 56 n° 1 (February 2019)  

Permalink

Epidémiologie et géographie / Marc Souris (2019)

Permalink