Let's say we have the following image



Is it possible to, for example, automatically draw single-line curves along all the roads (in red) from the map? If not then is it possible in some other application?

I guess you could use gimp to select the roads by color, extract the road network in a separated bitmap and then vectorize it with autotrace. The problem I see is that there are many details (text, road numbers, ...) to complicate the road extraction work...

I've heard that AutoTrace can do this sort of thing. However, I haven't tried it, so I don't know how well it works. See also the earlier thread on AutoTrace.

(Actually, looking at the map more closely, I don't think this is very feasible. It would probably be easier to trace the roads by hand.)

Unfortunately I also think that it would be best to do by hand. But, just maybe... For example - how to turn a shape similar to stroke of the to single line . If such operation is possible then there are some possibilities of automation.

Sas is correct. potrace (the default tracer) does not have the ability to find centerlines.

Autotrace does, and I beleive the linked post includes instructions on getting autotrace enabled under linux. Autotrace may be available as a standalone application under Windows.

-Rob A.

Got it! I thought it's for linux only. I'll give those roads a try one day and will report. Anyone, please post your results if you've tried already.