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Auteur Jochen Schiewe |
Documents disponibles écrits par cet auteur (9)
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Titre : Content-based image retrieval for map georeferencing Type de document : Article/Communication Auteurs : Jonas Luft, Auteur ; Jochen Schiewe, Auteur Editeur : International Cartographic Association ICA - Association cartographique internationale ACI Année de publication : 2021 Collection : Proceedings of the ICA num. 4 Conférence : ICC 2021, 30th ICA international cartographic conference 14/12/2021 18/12/2021 Florence Italie Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] appariement d'images
[Termes IGN] carte ancienne
[Termes IGN] carte numérisée
[Termes IGN] carte topographique
[Termes IGN] données localisées des bénévoles
[Termes IGN] géoréférencement indirect
[Termes IGN] mesure de similitude
[Termes IGN] recherche d'image basée sur le contenuRésumé : (auteur) In recent years, libraries have made great progress in digitising troves of historical maps with high-resolution scanners. Providing user-friendly information access for cultural heritage through spatial search and webGIS requires georeferencing of the hundreds of thousands of digitised maps. Georeferencing is usually done manually by finding “ground control points”, locations in the digital map image, whose identity is unambiguous and can easily be found in modern-day reference geodata/mapping data. To decide whether two symbols from different maps describe the same object, their semantic and spatial relations need to be matched. Automating this process is the only feasible way to georeference the immense quantities of maps in conceivable time. However, automated solutions for spatial matching quickly fail when faced with incomplete data – which is the greatest challenge when comparing maps of different ages or scales. These problems can be overcome by computing map similarity in the image domain. Treating maps as a special case of image processing allows efficient and robust matching and thus identification of geographical regions without the need to explicitly model semantics. We propose a method to encode worldwide reference VGI mapping data as image features, allowing the construction of an efficient lookup index. With this index, content-based image retrieval can be used for both geolocating a given map for georeferencing with high accuracy. We demonstrate our approach on hundreds of map sheets of different historical topographical survey map series, successfully georeferencing most of them within mere seconds. Numéro de notice : C2021-073 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Communication DOI : 10.5194/ica-proc-4-69-2021 Date de publication en ligne : 03/12/2021 En ligne : https://doi.org/10.5194/ica-proc-4-69-2021 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100007 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)
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 IGN] analyse de données
[Termes IGN] carte choroplèthe
[Termes IGN] couleur (rédaction cartographique)
[Termes IGN] enquête
[Termes IGN] erreur systématique
[Termes IGN] rédaction cartographique
[Termes IGN] vision
[Vedettes matières IGN] CartologieRésumé : (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 Affiliation des auteurs : non IGN 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
in KN, Journal of Cartography and Geographic Information > vol 69 n° 3 (September 2019) . - pp 217 - 228[article]
Titre : Task-oriented visualization approaches for landscape and urban change analysis Type de document : Article/Communication Auteurs : Jochen Schiewe, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique
[Termes IGN] carte choroplèthe
[Termes IGN] classification
[Termes IGN] visualisation cartographique
[Termes IGN] visualisation de données
[Vedettes matières IGN] GéovisualisationRésumé : (Auteur) Approaches to landscape and urban change analysis are still far away from being fully automatic or operational. For this reason, the concept of Geovisual Analytics is proposed, combining computational and visual/manual processing steps. This contribution concentrates on the latter part with the overall goal of improving its usability. For this purpose, a classification of tasks is created, which often occur in the context of change analysis. This serves as the basis for the assignment of suitable map types to change processing results. Beyond this, it is pointed out that in many cases an appropriate pre-processing of data is imperative to preserve or enhance certain spatial relationships or characteristics for visualization. This is demonstrated using the example of data classification prior to choropleth mapping. Methods are described which allow the preservation of local extreme values, large value differences between adjacent polygons, clusters, and hot/cold spots. Finally, discussing future research and developments, it will be stressed that the importance of visual methods in the context of big data change analysis will continue to increase, which is due to the particular ability of maps to generalize and reduce complex data to a minimum. Numéro de notice : A2018-352 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/ijgi7080288 Date de publication en ligne : 24/07/2018 En ligne : https://doi.org/10.3390/ijgi7080288 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90586
in ISPRS International journal of geo-information > vol 7 n° 8 (August 2018)[article]
Titre : Evaluating the effect of visually represented geodata uncertainty on decision-making: systematic review, lessons learned, and recommendations Type de document : Article/Communication Auteurs : Christoph Kinkeldey, Auteur ; Alan M. MacEachren, Auteur ; Maria Riveiro, Auteur ; Jochen Schiewe, Auteur Année de publication : 2017 Article en page(s) : pp 1 - 21 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] aide à la décision
[Termes IGN] incertitude des données
[Termes IGN] information géographique
[Termes IGN] visualisation de données
[Vedettes matières IGN] GéovisualisationRésumé : (auteur) For many years, uncertainty visualization has been a topic of research in several disparate fields, particularly in geographical visualization (geovisualization), information visualization, and scientific visualization. Multiple techniques have been proposed and implemented to visually depict uncertainty, but their evaluation has received less attention by the research community. In order to understand how uncertainty visualization influences reasoning and decision-making using spatial information in visual displays, this paper presents a comprehensive review of uncertainty visualization assessments from geovisualization and related fields. We systematically analyze characteristics of the studies under review, i.e., number of participants, tasks, evaluation metrics, etc. An extensive summary of findings with respect to the effects measured or the impact of different visualization techniques helps to identify commonalities and differences in the outcome. Based on this summary, we derive “lessons learned” and provide recommendations for carrying out evaluation of uncertainty visualizations. As a basis for systematic evaluation, we present a categorization of research foci related to evaluating the effects of uncertainty visualization on decision-making. By assigning the studies to categories, we identify gaps in the literature and suggest key research questions for the future. This paper is the second of two reviews on uncertainty visualization. It follows the first that covers the communication of uncertainty, to investigate the effects of uncertainty visualization on reasoning and decision-making. Numéro de notice : A2017-098 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/15230406.2015.1089792 En ligne : http://dx.doi.org/10.1080/15230406.2015.1089792 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84477
in Cartography and Geographic Information Science > Vol 44 n° 1 (January 2017) . - pp 1 - 21[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 032-2017011 RAB Revue Centre de documentation En réserve L003 Disponible
Titre : Visual encoding of acoustic parameters: framework and application to noise mapping Type de document : Article/Communication Auteurs : Jochen Schiewe, Auteur ; Beate Weninger, Auteur Année de publication : 2013 Article en page(s) : pp 332 - 344 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique
[Termes IGN] bruit (audition)
[Termes IGN] cartographie du bruit
[Termes IGN] plan d'exposition au bruit
[Termes IGN] représentation cartographique
[Termes IGN] variable visuelle
[Termes IGN] visualisation cartographiqueRésumé : (Auteur) Along with an increasing importance and awareness of sonic phenomena related to the human environment, there is a growing need for a comprehensive communication of sound information. The central goal of this contribution is the development of a systematic and comprehensive framework that considers the particular properties of sound phenomena. This framework is structured according to the acoustic quantities that shall be represented and consists of recommendations for their cartographical encoding. A proof of concept is given through the application to official strategic noise maps in the course of the Environmental Noise Directive. Those maps suffer from several weaknesses from a cartographical point of view (e.g. concerning colour schemes or band-like illustrations) which can be eliminated by applying some of the mentioned recommendations. Finally, it will be possible to derive valuable knowledge from our results for multimodal encoding and value transformation between senses. Numéro de notice : A2013-685 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1179/1743277412Y.0000000026 En ligne : https://doi.org/10.1179/1743277412Y.0000000026 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32821
in Cartographic journal (the) > vol 50 n° 4 (November 2013) . - pp 332 - 344[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 030-2013041 RAB Revue Centre de documentation En réserve L003 Disponible vol 34 n°6 - November 2010 - GeoVisualization and the Digital City Special issue of the International Cartographic Association Commission on GeoVisualization (Bulletin de Computers, Environment and Urban Systems) / Jason Dykes
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