This document discusses a semi-automatic process for detecting toponyms, or place names, on old maps. The approach uses image processing and connected component analysis to determine the location, extent, and orientation of features. It is a 3-step process involving background/foreground separation, feature detection, and feature linking. Some preliminary experiments detecting toponyms on maps from the 15th-18th centuries showed recall rates of around 50% and precision rates of around 31%. Future work aims to develop annotation tools to help index toponyms across collections of early geospatial documents.

1. Towards Semi-Automatic Annotation of
Toponyms on Old Maps
Rainer Simon, Peter Pilgerstorfer
Austrian Institute of Technology
Leif Isaksen
University of Southampton
Elton Barker
The Open University
September 19-20 2013 | 8th International Workshop on Digital Approaches to Cartographic Heritage, Rome, Italy

2. Map Digitization

3. But:
Search & discovery limited
by available catalog metadata!

4. Spatial Search?

5. (Caistor St. Edmund)
„Venta“
Toponyms?

6. (Whitchurch)
„Mediolanum“
Toponyms?

7. (Lincoln)
„Lindum“
Toponyms?

8. Transcription? OCR?
Remains a huge challenge.
We envision a semi-automatic process in which a
human expert is assisted in “annotation grunt work”

9. Goal:
detect toponyms on old maps
with open source tools.

10. Approach:
determine location, extent and orientation
using image processing and
connected component analysis

11. 3 Step Process:
Background/Foreground Separation
Feature Detection
Feature Linking

12. Step 1: Background/Foreground
Note: our steps still include manual tuning/intervention.

13. Step 2: Feature Detection

14. Step 3: Feature Linking

16. Some preliminary results:

17. Experiment #1
Ptolemaic Map of the British Isles, ca. 1480
© The British Library Board. Harley MS 7182 ff.. 60v-61.

18. Experiment #2
Josephinische Landesaufnahme: Gebiet von Moos-
kirchen bis Grazer Feld, Österreich, 1764-1787.

19. Experiment #3
Salvator Oliva, Mediterranean.
Portolan Atlas, Marseilles,
1619.
• 333 toponyms counted
• 532 detections
• ~50% recall
• ~31% precision

20. http://rsimon.github.com/toponym_identification
Full-resolution views at

21. Future work – Pelagios 3:
• Provide an index of toponyms in early
geospatial documents
• Create assistive annotation tools to enhance
the index
• Develop an “analysis workbench” to conduct
visual & statistical comparions between
different collections and documents

22. Thank you for your attention
http://pelagios-project.blogspot.co.uk
rainer.simon@ait.ac.at
@aboutgeo