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Visual clutter reduction in zoomable proportional point symbol maps / Tomasz Opach 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. 347 - 367 Titre : Visual clutter reduction in zoomable proportional point symbol maps Type de document : Article/Communication Auteurs : Tomasz Opach, Auteur ; Jolanta Korycka-Skorupa, Auteur ; Izabela Karsznia, Auteur ; et al., Auteur Année de publication : 2019 Article en page(s) : pp. 347 - 367 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie numérique [Termes IGN] approche holistique [Termes IGN] carte cognitive [Termes IGN] étude empirique [Termes IGN] figuré ponctuel [Termes IGN] fouillis d'échos [Termes IGN] modèle analytique [Termes IGN] précision cartographique [Termes IGN] test statistique Résumé : (auteur) Proportional point symbols are commonly used in map displays. However, when such displays are zoomed out, the available map space shrinks and consequently symbols overlap and the display suffers from visual clutter. Therefore, solutions are needed to reduce visual clutter in zoomable map displays that contain proportional point symbols. The authors add to the body of knowledge through the investigation of the performance of three solutions: aggregation of unit areas, the displacement of overlapping symbols, and modified symbolization; four variations of modified symbolization are examined in detail. The original study begins with a consideration of the strengths and weaknesses of the solutions, with an emphasis on information loss. Thereafter, user sessions with 165 participants are arranged to gain empirical evidence of the performance of the solutions. The results reveal that although participants zoom out the map to zoom levels that implement visual clutter reduction techniques, they tend to zoom in the map and pan it to examine specific areas. Moreover, they willingly use the map with aggregated unit areas in cases when the solution facilitates task accomplishment. A certain amount of skepticism attaches to the solution that displaces overlapping symbols. Numéro de notice : A2019-202 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2018.1490202 Date de publication en ligne : 10/07/2018 En ligne : https://doi.org/10.1080/15230406.2018.1490202 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92661 [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)  

Public [article]  inCartographic journal (the) > Vol 56 n° 2 (May 2019) . - pp 117 - 133 Titre : Cartographic symbol design considerations for the space–time cube Type de document : Article/Communication Auteurs : Christopher League, Auteur ; Patrick Kennelly, Auteur Année de publication : 2019 Article en page(s) : pp 117 - 133 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] conception cartographique [Termes IGN] cube espace-temps [Termes IGN] données localisées 2D [Termes IGN] données spatiotemporelles [Termes IGN] figuré ponctuel [Termes IGN] saturation de la couleur [Termes IGN] sémiologie graphique [Termes IGN] symbole graphique 3D [Vedettes matières IGN] Géovisualisation Résumé : (Auteur) The cartographic representation of geographic phenomena in the space–time cube comes with special challenges and opportunities when compared with two-dimensional maps. While the added dimension allows the display of attributes that vary with time, it is difficult to display rapidly varying temporal data given the limited display height. In this study, we adapt 2D cyclic point symbols to construct 3D surfaces designed along a helical path for the space–time cube. We demonstrate how these complex 3D helical surfaces can display detailed data, including data reported daily over 100 years and data reported in four-hour intervals over a year. To create the point symbols, each value is plotted along the curve of a helix, with each turn of the helix representing one year or week, respectively. The model is modified by varying the radii from the time axis to all points using the attribute value, in these cases maximum daily temperature and four-hourly ridership, and then creating a triangulated surface from the resulting points. Using techniques common to terrain representation, we apply hue and saturation to the surface based on attribute values, and lightness based on relief shading. Multiple surfaces can be displayed in a space–time cube with a consistent time interval facing the viewer, and the surfaces or viewer perspective can be rotated to display synchronized variations. We see this method as one example of how cartographic design can refine or enhance operations in the space–time cube. Numéro de notice : A2019-239 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00087041.2018.1533291 Date de publication en ligne : 29/05/2019 En ligne : https://doi.org/10.1080/00087041.2018.1533291 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92931 [article]

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030-2019021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

The differentiation of point symbols using selected visual variables in the mobile augmented reality system / Łukasz Halik in Cartographic journal (the), Vol 54 n° 2 (May 2017)  

Public [article]  inCartographic journal (the) > Vol 54 n° 2 (May 2017) . - pp 147 - 156 Titre : The differentiation of point symbols using selected visual variables in the mobile augmented reality system Type de document : Article/Communication Auteurs : Łukasz Halik, Auteur ; Beata Medyńska-Gulij, Auteur Année de publication : 2017 Article en page(s) : pp 147 - 156 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Rédaction cartographique [Termes IGN] appareil portable [Termes IGN] figuré ponctuel [Termes IGN] navigation pédestre [Termes IGN] piéton [Termes IGN] Pologne [Termes IGN] réalité augmentée [Termes IGN] seuillage [Termes IGN] symbole graphique [Termes IGN] test de performance [Termes IGN] variable visuelle Résumé : (Auteur) On the basis of initial studies devoted to a better understanding of how the public user (a pedestrian in the city) perceives cartographic symbols in the mobile augmented reality system, we present an attempt to determine the threshold values of differentiation for three visual variables. The variables of size, transparency, and focus were implemented into image point symbols representing five types of objects. The set of symbols was designed in accordance with the rules of cartographic design taking into consideration an analysis of 19 professional tourist works. The symbols were presented on the screen of a mobile device in a system imitating the augmented reality system against four different backgrounds: white, a wall, and two typical urban landscapes. The results of an internet survey conducted using a tablet at four locations in Poznan (Poland) allowed us to determine the following: threshold differentiation values for the analysed variables, indication of the dependence on the type of background displayed on the mobile device in augmented reality, and the advantage of using a combination of visual variables. Numéro de notice : A2017-324 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00087041.2016.1253144 En ligne : http://dx.doi.org/10.1080/00087041.2016.1253144 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85397 [article]

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030-2017021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Clutter reduction methods for point symbols in map mashups / Jari Korpi in Cartographic journal (the), vol 50 n° 3 (August 2013)  

Public [article]  inCartographic journal (the) > vol 50 n° 3 (August 2013) . - pp 257 - 265 Titre : Clutter reduction methods for point symbols in map mashups Type de document : Article/Communication Auteurs : Jari Korpi, Auteur ; Paula Ahonen-Rainio, Auteur Année de publication : 2013 Article en page(s) : pp 257 - 265 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] agrégation de détails [Termes IGN] application composite [Termes IGN] figuré ponctuel [Termes IGN] généralisation cartographique automatisée [Termes IGN] placement automatique des signes conventionnels [Termes IGN] réduction Résumé : (Auteur) Map mashups are often visually chaotic and methods for solving this chaos are required. We introduce a set of clutter reduction criteria for evaluating methods to reduce clutter in map mashups. We present a synthesis of cartographic generalisation operators for point data and clutter reduction methods used in information visualisation and evaluate the methods against the criteria. The resulting evaluation table can be used in finding suitable clutter reduction methods for cases of map mashups with different primary criteria, and more specifically in finding methods that cover each others’ limitations. Numéro de notice : A2013-465 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/1743277413Y.0000000065 En ligne : https://doi.org/10.1179/1743277413Y.0000000065 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32603 [article]

Exemplaires(1)

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030-2013031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

From LiDAR data to forest representation on multi-scale / Freiderike Schwarzbach in Cartographic journal (the), vol 50 n° 1 (February 2013)  

Public [article]  inCartographic journal (the) > vol 50 n° 1 (February 2013) . - pp 33 - 42 Titre : From LiDAR data to forest representation on multi-scale Type de document : Article/Communication Auteurs : Freiderike Schwarzbach, Auteur ; Juha Oksasnen, Auteur ; et al., Auteur Année de publication : 2013 Article en page(s) : pp 33 - 42 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques [Termes IGN] arbre (flore) [Termes IGN] carte de la végétation [Termes IGN] conception cartographique [Termes IGN] données lidar [Termes IGN] figuré ponctuel [Termes IGN] généralisation cartographique [Termes IGN] orthoimage couleur [Termes IGN] rédaction cartographique [Termes IGN] représentation multiple Résumé : (Auteur) The paper describes processing methods for portraying forest areas on maps utilizing point symbols. The forest map design is based on the use of individual tree data, which is detected from airborne laser scanning data and colour-infrared orthophotos. Several generalisation and symbolisation approaches have been tested in order to use the tree data set for cartographic purposes. Our generalisation method differentiates between trees in dense forests and tree structures in open areas, such as isolated trees, tree groups, tree rows and sparsely scattered trees. The tree symbols are integrated visually with the other map content. The results show that the production of attractive and useful maps requires an advanced generalisation method due to the massive amount of tree objects extracted from the laser scanning data as well as a generalisation level and a symbol type for the trees that are carefully chosen according to the map scale. Furthermore, sophisticated visualisation methods are needed for composing the maps. The created maps are part of a project that aims at supporting outdoor activities using multi-scale maps as part of a multi-publishing service. Numéro de notice : A2013-187 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/1743277412Y.0000000015 En ligne : https://doi.org/10.1179/1743277412Y.0000000015 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32325 [article]

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La représentation des données géographiques / Michèle Béguin (2010)

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Méthodes de la cartographie / B. Rouleau (2002)

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A dot matrix method of portraying continuous statistical surfaces / R.E. Groop in American cartographer (the), vol 9 n° 2 (October 1982)  

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Figuré du terrain / Jean Carré (1971)

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Phénomènes des points de généralisation / L. Ratajski in Annuaire international de cartographie, n° 7 (1967)

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