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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]

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]

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Robust multisource remote sensing image registration method based on scene shape similarity / Ming Hao in Photogrammetric Engineering & Remote Sensing, PERS, vol 85 n° 10 (October 2019)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 85 n° 10 (October 2019) . - pp 725 - 736 Titre : Robust multisource remote sensing image registration method based on scene shape similarity Type de document : Article/Communication Auteurs : Ming Hao, Auteur ; Jian Jin, Auteur ; Mengchao Zhou, Auteur ; et al., Auteur Année de publication : 2019 Article en page(s) : pp 725 - 736 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte [Termes descripteurs IGN] appariement de modèles [Termes descripteurs IGN] coefficient de corrélation [Termes descripteurs IGN] figuré du terrain [Termes descripteurs IGN] image multibande [Termes descripteurs IGN] image radar moirée [Termes descripteurs IGN] niveau de gris (image) [Termes descripteurs IGN] point de liaison (imagerie) [Termes descripteurs IGN] superposition d'images [Termes descripteurs IGN] temps de pose [Termes descripteurs IGN] transformation linéaire Résumé : (Auteur) Image registration is an indispensable component of remote sensing applications, such as disaster monitoring, change detection, and classification. Grayscale differences and geometric distortions often occur among multisource images due to their different imaging mechanisms, thus making it difficult to acquire feature points and match corresponding points. This article proposes a scene shape similarity feature (SSSF) descriptor based on scene shape features and shape context algorithms. A new similarity measure called SSSFncc is then defined by computing the normalized correlation coefficient of the SSSF descriptors between multisource remote sensing images. Furthermore, the tie points between the reference and the sensed image are extracted via a template matching strategy. A global consistency check method is then used to remove the mismatched tie points. Finally, a piecewise linear transform model is selected to rectify the remote sensing image. The proposed SSSFncc aims to extract the scene shape similarity between multisource images. The accuracy of the proposed SSSFncc is evaluated using five pairs of experimental images from optical, synthetic aperture radar, and map data. Registration results demonstrate that the SSSFncc similarity measure is robust enough for complex nonlinear grayscale differences among multisource remote sensing images. The proposed method achieves more reliable registration outcomes compared with other popular methods. Numéro de notice : A2019-521 Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.14358/PERS.85.10.725 date de publication en ligne : 01/10/2019 En ligne : https://doi.org/10.14358/PERS.85.10.725 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93989 [article]

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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]

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 descripteurs IGN] approche holistique [Termes descripteurs IGN] carte cognitive [Termes descripteurs IGN] etude empirique [Termes descripteurs IGN] figuré ponctuel [Termes descripteurs IGN] fouillis d'échos [Termes descripteurs IGN] modèle analytique [Termes descripteurs IGN] précision cartographique [Termes descripteurs 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 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)  

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Bertin’s matrix concepts reconsidered: transformations of semantics and semiotics to support geovisualization use / Francis Harvey in Cartography and Geographic Information Science, vol 46 n° 2 (March 2019)  

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Comparing finite and infinitesimal map distortion measures / Krisztian Kerkovits in International journal of cartography, vol 5 n° 1 (March 2019)  

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Expanding the Sémiologie Graphique for contemporary cartography, some ideas from visual semiotics, art history and design / Laurent Jégou in Cartography and Geographic Information Science, vol 46 n° 2 (March 2019)  

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(re)Considering Bertin in the age of big data and visual analytics / Alan M. MacEachren in Cartography and Geographic Information Science, vol 46 n° 2 (March 2019)  

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Cartographic design and the space–time cube / Irma Kveladze in Cartographic journal (the), Vol 56 n° 1 (February 2019)  

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Map symbols for crisis mapping : challenges and prospects / John C. Kostelnick in Cartographic journal (the), Vol 56 n° 1 (February 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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Fifty shades of Roboto: text design choices and categories in multi-scale maps / Sébastien Biniek (2019)    

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Automated Swiss-style relief shading and rock hachuring / Roman Geisthövel in Cartographic journal (the), Vol 55 n° 4 (November 2018)  

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