This document describes two online tools for exploring historical maps: Old Maps Online and Georeferencer. Old Maps Online allows users to search over 130,000 digitized historical maps and links back to the original archives. Georeferencer is a crowdsourcing tool that allows users to georeference digitized maps by adding ground control points and cutlines, with revisions tracked. Both tools provide visualization of georeferenced maps through overlays on Google Maps, Google Earth, and other platforms.

1. Old Maps Online
and
Georeferencer
Václav Klusák (vaclav.klusak@klokantech.com)

2. www.oldmapsonline.org

4. • Time and scale filters
• Full-text filter
• Ordered by similarity to query bounds
• Immediate feedback

5. • Data come from libraries and archives
• Approx. 130 000 maps now
• We link back to the original sites

7. www.mapranksearch.com

8. • Collection of records with their attributes
• Records must have geometries (WKT)
• Dublin Core inspired metadata
• Custom attributes
• Query by bounding box

9. • Optimized for fast frequent searches and
infrequent batched updates
• Read-only
• Machine-dependent file format
• WAH compressed bitmap indices
• Response time independent from query
bounds

10. • FastCGI application
• OpenSearch queries
• JSON results
• UI based on Google Closure Javascript
Toolkit
• Google Maps, OpenLayers 3 or Leaflet

11. Georeferencer
www.georeferencer.com

12. • Geared towards libraries and archives
• Enables them to georeference large
collections of digitized maps by
crowdsourcing the effort
• Rewards users with attractive vizualizations
• Development sponsored by Moravian
Library

14. • Users add GCPs and cutlines to maps
• Revision history is stored
• Quality control by reviewers

17. • Google Maps, WMS and WMTS overlays
• 3D view with Google Earth
• Accuracy analysis with MapAnalyst
• MARC 034
• gdal_georeferencer.py
• Linked data annotations in development

19. http://www.georeferencer.com/

20. • Image servers as data sources
• ContentDM, IIP Image, Zoomify, ...
• Only thumbnails are stored
• Same metadata as in MapRank

21. Klokan Technologies GmbH
info@klokantech.com