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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]

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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] Rédaction cartographique [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]

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)  

Public [article]  inCartographic perspectives > n°92 (2019) . - 15 p Titre : “Mapping-with”: The Politics of (Counter-)classification in OpenStreetMap Type de document : Article/Communication Auteurs : Clancy Wilmott, Auteur Année de publication : 2019 Article en page(s) : 15 p Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes descripteurs IGN] analyse sémantique [Termes descripteurs IGN] cartographie collaborative [Termes descripteurs IGN] classification [Termes descripteurs IGN] conception cartographique [Termes descripteurs IGN] données localisées des bénévoles [Termes descripteurs IGN] logique [Termes descripteurs IGN] OpenStreetMap [Termes descripteurs IGN] taxinomie [Vedettes matières IGN] Cartologie Résumé : (auteur) In this paper I consider how debates in critical cartography about the classificatory and calculative logics of the map might be renegotiated through the concepts of “making-kin,” “sympoesis,” and the chthonic. Between Haraway’s (2014) Staying With The Trouble and Foucault’s (2002) writings on mathesis and taxinomia in The Order of Things, I argue that a more situated understanding of mapping—as an entanglement between people, tools, landscapes, cultures—might realise a more open, and more attentive, way of mapping. I return to the popular case study, OpenStreetMap, to excavate how the use and misuse of taxonomic and mathematical logics through its collaborative and amateur affordabilities shed light on different ways of sorting-with the world. I argue that, in the unexpected emergence of proposed classifications (and despite the disciplining power of cartographic discourses), roots of a new and more inclusive cartography linger in the archive, waiting to be fertilised. Numéro de notice : A2019-419 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14714/CP92.1451 date de publication en ligne : 24/07/2019 En ligne : https://doi.org/10.14714/CP92.1451 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93548 [article]

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)  

Public [article]  inCartography and Geographic Information Science > Vol 46 n° 4 (July 2019) . - pp 311 - 333 Titre : Graphically supported evaluation of mapping techniques used in presenting spatial accessibility Type de document : Article/Communication Auteurs : Lukasz Wielebski, Auteur ; Beata Medyńska-Gulij, Auteur Année de publication : 2019 Article en page(s) : pp 311 - 333 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Rédaction cartographique [Termes descripteurs IGN] accessibilité [Termes descripteurs IGN] analyse spatiale [Termes descripteurs IGN] charte graphique [Termes descripteurs IGN] conception cartographique [Termes descripteurs IGN] lisibilité perceptive [Termes descripteurs IGN] questionnaire [Termes descripteurs IGN] test de performance [Termes descripteurs IGN] visualisation cartographique Résumé : (Auteur) Given the rising availability of alternative ways of spatial data mapping, there is a growing need to study their usability. An important aspect here is the diversity of the cartographic visualizations that are used to draw conclusions about the usability of various mapping techniques. In our study we evaluated the usability of six various mapping techniques used in presenting spatial accessibility, taking into consideration four components: effectiveness and efficiency (objective criteria) and graphical attractiveness and user-perceived effectiveness (subjective criteria). Using Internet questionnaires, we conducted a graphical perception experiment with respondents performing tasks on a hypothetical monocentric road network model displayed using mapping techniques of spatial accessibility, differing in the applied parameters of graphical and non-graphical factors influencing effectiveness and efficiency. The results showed that non-graphical factors had a greater influence than the graphical factors. In total usability comparison the three-dimensional (3D) point technique was ranked the highest, while the worst result was achieved by the 3D area technique. The proposed graphical form of study results made it possible to compare the influence of various effectiveness factors, to analyze mapping techniques in terms of considered criteria and finally to present their total usability using a chart inspired by Uhorczak’s typogram. Numéro de notice : A2019-200 Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2018.1479311 En ligne : https://doi.org/10.1080/15230406.2018.1479311 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92655 [article]

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

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

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

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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)  

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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)  

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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)  

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Epidémiologie et géographie / Marc Souris (2019)

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Fifty shades of Roboto: text design choices and categories in multi-scale maps / Sébastien Biniek (2019)    

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Réaliser les cartes d’une revue grand public, de la conception à l’animation / Fanny Privat (2019) 

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Rendu et représentation graphiques d’informations spatio-temporelles / Sidonie Christophe (2019)    

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