[Qgis-user] Centre of the roads from polygons to lines

[Jukka Rahkonen]

Matej Mailing <mailing at ...> writes:

> 
> Hi,
> 
> I have a layer that contains roads in polygons and I need to get
> central lines of the polygons. When I convert directly from polygons
> to lines, I get two lines for each part of the road representing road
> "boundaries" which isn't good.
> 
> What is the best way to achieve it?

You may want to have a look at the OpenJUMP skeletonizer plugin, if not else
then just getting some inspiration.
http://sourceforge.net/projects/jump-pilot/files/OpenJUMP_plugins/More%20Plugins/JUMP%20Skeletonizer%20Plugin/

There seems to be an article about skeletonizing with PostGIS
http://ageoguy.blogspot.fi/2010/12/squelettisation.html

-Jukka Rahkonen-