Map generalisation is the process of modifying map features to appear visually clearer and simpler at smaller scales. It has traditionally been seen as a computational cartography problem that can be addressed through algorithms that automate tasks like feature simplification and displacement. However, generalisation is a complex task that also requires knowledge-based solutions to properly orchestrate algorithms and evaluate results. While progress has been made in developing individual generalisation algorithms, fully automating the entire generalisation process from multiple data sources down to many map scales remains an open challenge that computational cartography continues working to address.

1. Is Map Generalisation a
Computational Cartography
Problem?
Guillaume Touya, IGN, Univ Gustave Eiffel

2. Spatial
data
map
Symbolised for 1:15000 Symbolised for 1:50000
Real size 1:50k map
Map
generalisation
2

3. [de Berg et al. 1998]

4. data
knowledge
Generalisation orchestration
map
enrichment
Formali-
sation
4
Algorithms
Evaluation
Automated map generalisation
Partitioning

5. Multi-scale zoomable maps
1:10k
1:25k
1:250k
1:100k
1:500k

6. Thematic maps
[Raposo et al. 2020]

7. Data Enrichment
[Savino & Touya 2015]

8. Generalisation algorithms
[van Goethem et al. 2021]

9. Generalisation algorithms
[Touya & Girres 2014]

10. Generalisation algorithms
[Lokhat & Touya 2016]

11. Generalisation
algorithms
[Lokhat & Touya 2021]

12. Schematisation vs generalisation
[Buchin et al. 2016]
12

13. Topography/Schematization Mix

15. Naive cartography

16. Orchestration
of algorithms
[Ruas & Plazanet 1996]

17. Orchestration of
algorithms
[Harrie 1999]

18. Generalisation evaluation
« Building area > 0.4 map mm² »
« Building granularity > 0.1 map mm »
« Building alignments should be preserved »
« Building/road distance > 0.1 map mm »
[Touya 2012]

19. Generalisation evaluation
Better?
« Building area > 0.4 map mm² »
« Building granularity > 0.1 map mm »
« Building alignments should be preserved »
« Building/road distance > 0.1 map mm »
[Touya 2012]

20. Continuous generalisation
[Peng & Touya 2017]

21. Continuous generalisation
Presentation by Martijn Meijers

22. Multi-scale interactions
[van Dijk & Haunert 2014]

23. So, is map generalisation a
computational cartography
problem?

25. Computational
cartography vs
deep learning
[Courtial et al. 2021]

26. Is Map Generalisation a
Computational Cartography
Problem?
Guillaume Touya, IGN, Univ Gustave Eiffel
Any question?