There are dozens of things that I could go into, but I suppose hte most important question is:
 
Which line thinning algorithm are you using?  
 
Without knowing more about that, I would try thinning lines using the Douglas-Peucker algorithm (and I really don't understand why anyone would use anything else). I've written a tool to do this, and I'm sure others have as well.   Start by using the raster grid size (i.e. the size of a pixel projected onto the Earth) as the tolerance.  You can increase the tolerance further, to generalize to maps at larger scales.
 
Hope this helps
Spencer
 
 
 
 
 
 
 
 
 
 
 
 
 


From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Morrier, Steve
Sent: Monday, November 21, 2005 3:14 PM
To: [email protected]
Subject: [MI-L] Intelligent Node Thinning

Hi All,
 
Does anyone know of a tool that will do intelligent node thinning? We have extracted a large number of forest blocks from 75cm aerial photography using a spectral classification. The classification produces a very "stepped" looking polygon with far too many nodes/points. I would like to run a combination of smooth and generalize on the polygons. The problem is the smooth seems to add more nodes and the generalize ends up really altering the shape of the polygon. It would be nice to be able to specify an angle and a distance that you could choose to keep or drop nodes based on the angle to the next node and the distance. Does anything like this exist? Thanks very much.
 
Steve
_______________________________________________
MapInfo-L mailing list
[email protected]
http://www.directionsmag.com/mailman/listinfo/mapinfo-l

Reply via email to