I am looking for existing solutions (softwares, libraries, methods, etc.) to automate the generalisation/simplification of geographical data as presented there, and also there.
Do you know and use some tools to simplify your geographical data?
I already had a look at these ones:
- maptimize to simplify the representation of KML marker layers,
- Modelbuilder by ESRI
- Radius clarity by laserscan
- mapshaper to compute online filtering algorithms on geometries,
- Axpand by axes-systems
The ICA commission on generalisation and multiple representation website is a huge information source on this topic. Many papers presents advanced methods and use cases related to this topic.
The very famous douglass & peucker filtering algorithm is often used for geometrical simplification and is present in almost all GIS softwares. However, its effect is to make geometries very bony/angular without really simplifying the geometry shape. For example, it is not very adapted for lines representing roads or rivers, that have to be smooth and not angular.
Best Answer
Automatic generalization algorithms are not yet a complete solution, they still often make decisions a careful cartographer would abhor. Natural Earth has a good background article on how their approaches to generalizing features, a multi-step manual process. Axpand claims the Swiss Topography Office had an 80% success rate with automatic generalization when using their software with topographic maps.
You've mentioned in a few responses that you don't like the 'bony' geometries produced by many automated solutions, could you explain what aspects of the data you'd like to retain? Are you interested in positional accuracy of the results, or more in the aesthetics? That will help give us a sense of where a solution might lie.