[gdal-dev] Smoothing polygons

Howard Butler hobu.inc at gmail.com
Mon May 12 17:33:47 EDT 2008


You want a Douglas-Peucker algorithm?  http://mappinghacks.com/2008/05/05/douglas-peucker-line-simplification-in-python/

DP generalization is in GEOS too, I think, but not available to the C  
API.


On May 12, 2008, at 4:26 PM, Clay, Bruce wrote:

> With the help of some folks on this forum I have successfully  
> managed to create polygons that represent the coverage area of a set  
> of geo-data points.  The operation does quite smoothly and fairly  
> fast.  I am don’t to one final operation that I have searched both  
> GDAL/OGR and GEOS API and have not found.
>
> Before I start coding I wanted to ask if anyone knows of an existing  
> operation that I missed that will smooth the edges and simplify the  
> resultant polygons.  The attached files show the buffered points as  
> overlapping polygons and the final merged polygon.  The merged set  
> is a result of applying a buffer to a GeometryCollection.  If the  
> images make it though the mail filters you can see that the edges of  
> the polygons have a scalloped effect.  If I can smooth the edged it  
> should reduce the stored geometry size.
>
> Any thoughts would be greatly appreciated.
>
> Bruce
>
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> polygons 
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