Centre de documentation
scientifique

Recognizing text in raster maps / Yao-Yi Chiang in Geoinformatica, vol 19 n° 1 (January - March 2015)  

Public [article]  inGeoinformatica > vol 19 n° 1 (January - March 2015) . - pp 1 - 27 Titre : Recognizing text in raster maps Type de document : Article/Communication Auteurs : Yao-Yi Chiang, Auteur ; Craig A. Knoblock, Auteur Année de publication : 2015 Article en page(s) : pp 1 - 27 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] carte ancienne [Termes IGN] données maillées [Termes IGN] information géographique [Termes IGN] placement des écritures [Termes IGN] reconnaissance de caractères [Termes IGN] système d'information cartographique [Termes IGN] toponyme Résumé : (auteur) Text labels in maps provide valuable geographic information by associating place names with locations. This information from historical maps is especially important since historical maps are very often the only source of past information about the earth. Recognizing the text labels is challenging because heterogeneous raster maps have varying image quality and complex map contents. In addition, the labels within a map do not follow a fixed orientation and can have various font types and sizes. Previous approaches typically handle a specific type of map or require intensive manual work. This paper presents a general approach that requires a small amount of user effort to semi-automatically recognize text labels in heterogeneous raster maps. Our approach exploits a few examples of text areas to extract text pixels and employs cartographic labeling principles to locate individual text labels. Each text label is then rotated automatically to horizontal and processed by conventional OCR software for character recognition. We compared our approach to a state-of-art commercial OCR product using 15 raster maps from 10 sources. Our evaluation shows that our approach enabled the commercial OCR product to handle raster maps and together produced significant higher text recognition accuracy than using the commercial OCR alone. Numéro de notice : A2015-484 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-014-0203-9 Date de publication en ligne : 21/02/2014 En ligne : https://doi.org/10.1007/s10707-014-0203-9 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77246 [article]

Proceedings of the Sixth ACM SIGSPATIAL International Workshop on Computational Transportation Science / Craig A. Knoblock (2013)  

Public Titre : Proceedings of the Sixth ACM SIGSPATIAL International Workshop on Computational Transportation Science Type de document : Actes de congrès Auteurs : Craig A. Knoblock, Éditeur scientifique ; Markus Schneider, Éditeur scientifique Editeur : New York [Etats-Unis] : Association for computing machinery ACM Année de publication : 2013 Conférence : IWCTS 2013, 6th ACM SIGSPATIAL International Workshop on Computational Transportation Science 05/11/2013 08/11/2013 Orlando Floride - Etats-Unis Proceedings ACM ISBN/ISSN/EAN : 978-1-4503-2527-1 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] informatique [Termes IGN] système d'information géographique [Termes IGN] transport Numéro de notice : 17129 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/INFORMATIQUE Nature : Actes En ligne : http://dl.acm.org/citation.cfm?id=2533828 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80065

Contient

• Extracting semantics of individual places from movement data by analyzing temporal patterns of visits / Gennady Andrienko (2013)    
• A 3D geospatial registration service for street level co-visualization of 2D vector maps / Quoc-Dinh Nguyen (2013)  
• 2D arrangement-based hierarchical spatial partitioning: an application to pedestrian network generation / Murat Yirci (2013)  
• Accentuating focus maps via partial schematization / Thomas van Dijk (2013)    

Automatic and accurate extraction of road intersections from raster maps / Yao-Yi Chiang in Geoinformatica, vol 13 n° 2 (June 2009)  

Public [article]  inGeoinformatica > vol 13 n° 2 (June 2009) . - pp 121 - 157 Titre : Automatic and accurate extraction of road intersections from raster maps Type de document : Article/Communication Auteurs : Yao-Yi Chiang, Auteur ; C. Shahabi, Auteur ; Craig A. Knoblock, Auteur ; C.C. Chen, Auteur Année de publication : 2009 Article en page(s) : pp 121 - 157 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] carrefour [Termes IGN] carte numérique [Termes IGN] conflation [Termes IGN] connexité (topologie) [Termes IGN] données maillées [Termes IGN] extraction automatique [Termes IGN] extraction du réseau routier [Termes IGN] intégration de données [Termes IGN] réseau routier Résumé : (Auteur) Since maps are widely available for many areas around the globe, they provide a valuable resource to help understand other geospatial sources such as to identify roads or to annotate buildings in imagery. To utilize the maps for understanding other geospatial sources, one of the most valuable types of information we need from the map is the road network, because the roads are common features used across different geospatial data sets. Specifically, the set of road intersections of the map provides key information about the road network, which includes the location of the road junctions, the number of roads that meet at the intersections (i.e., connectivity), and the orientations of these roads. The set of road intersections helps to identify roads on imagery by serving as initial seed templates to locate road pixels. Moreover, a conflation system can use the road intersections as reference features (i.e., control point set) to align the map with other geospatial sources, such as aerial imagery or vector data. In this paper, we present a framework for automatically and accurately extracting road intersections from raster maps. Identifying the road intersections is difficult because raster maps typically contain much information such as roads, symbols, characters, or even contour lines. We combine a variety of image processing and graphics recognition methods to automatically separate roads from the raster map and then extract the road intersections. The extracted information includes a set of road intersection positions, the road connectivity, and road orientations. For the problem of road intersection extraction, our approach achieves over 95% precision (correctness) with over 75% recall (completeness) on average on a set of 70 raster maps from a variety of sources. Copyright Springer Numéro de notice : A2009-073 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s10707-008-0046-3 En ligne : https://doi.org/10.1007/s10707-008-0046-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29703 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-09021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Extracting geographic features from the Internet to automatically build detailed regional gazetteers / D. Goldberg in International journal of geographical information science IJGIS, vol 23 n° 1-2 (january 2009)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 23 n° 1-2 (january 2009) . - pp 93 - 128 Titre : Extracting geographic features from the Internet to automatically build detailed regional gazetteers Type de document : Article/Communication Auteurs : D. Goldberg, Auteur ; J. Wilson, Auteur ; Craig A. Knoblock, Auteur Année de publication : 2009 Article en page(s) : pp 93 - 128 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] acquisition de données [Termes IGN] extraction de données [Termes IGN] internet [Termes IGN] objet géographique [Termes IGN] répertoire toponymique Résumé : (Auteur) The utility of every imaginable application which incorporates a gazetteer hinges on the simple fact that the resulting system will only be as useful, complete, or accurate as the underlying gazetteer itself. A major issue confronting gazetteers utilized in systems today is that they are not complete and measures of their accuracy are largely unknown. In this paper we describe a methodology which addresses this problem by automatically generating highly complete and detailed regional gazetteers from Internet sources. We utilize information extraction and integration techniques to automatically obtain geographic features and associated footprints and feature types from freely and widely available online data which could be applied to create a gazetteer for nearly any area. We discuss the distinguishing characteristics of the generated gazetteer and extend previous work to define measures which can be used to assess the completeness and accuracy of gazetteers. Using these measures, the generated gazetteer is evaluated against the Alexandria Digital Library Gazetteer and the Los Angeles Comprehensive Bibliographic Database. Our results indicate that a gazetteer created by our methods will be at least as complete as any gazetteer currently available for certain feature classes, while falling short in others. We conclude by offering suggestions to address these shortcomings. Copyright Taylor & Francis Numéro de notice : A2009-129 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810802577262 En ligne : https://doi.org/10.1080/13658810802577262 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29759 [article]

Exemplaires(2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
079-09011	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-09012	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Automatically and accurately conflating raster maps with orthoimagery / C.C. Chen in Geoinformatica, vol 12 n° 3 (September - November 2008)  

Public [article]  inGeoinformatica > vol 12 n° 3 (September - November 2008) . - pp 377 - 410 Titre : Automatically and accurately conflating raster maps with orthoimagery Type de document : Article/Communication Auteurs : C.C. Chen, Auteur ; Craig A. Knoblock, Auteur ; C. Shahabi, Auteur Année de publication : 2008 Article en page(s) : pp 377 - 410 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique [Termes IGN] appariement de points [Termes IGN] carrefour [Termes IGN] carte thématique [Termes IGN] conflation [Termes IGN] données maillées [Termes IGN] données vectorielles [Termes IGN] orthoimage [Termes IGN] réseau routier [Termes IGN] transformation élastique Résumé : (Auteur) Recent growth of geospatial information online has made it possible to access various maps and orthoimagery. Conflating these maps and imagery can create images that combine the visual appeal of imagery with the attribution information from maps. The existing systems require human intervention to conflate maps with imagery. We present a novel approach that utilizes vector datasets as “glue” to automatically conflate street maps with imagery. First, our approach extracts road intersections from imagery and maps as control points. Then, it aligns the two point sets by computing the matched point pattern. Finally, it aligns maps with imagery based on the matched pattern. The experiments show that our approach can conflate various maps with imagery, such that in our experiments on TIGER-maps covering part of St. Louis county, MO, 85.2% of the conflated map roads are within 10.8 m from the actual roads compared to 51.7% for the original and georeferenced TIGER-map roads. Copyright Springer Numéro de notice : A2008-285 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1007/s10707-007-0033-0 En ligne : https://doi.org/10.1007/s10707-007-0033-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29278 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
057-08031	RAB	Revue	Centre de documentation	En réserve L003	Disponible

Automatically conflating road vector data with orthoimagery / C.C. Chen in Geoinformatica, vol 10 n° 4 (December 2006)  

Permalink