[postgis-users] How to generalize or simplify a Polygon

[strk]

The extension works for both lines and polygons.
Does not try to solve the self-intersection problem.
Simplified features can be stored back to db.

--strk;

spoerri wrote:
> I'm not sure if this was mentioned before, but earlier this summer their was a 
> post on the list by somebody that implemented the D-P algorithm on lines as 
> an extension/function to PostGIS. This may be a good starting point to also 
> simplify polygons (if required).
> 
> Along this line, I was also think if it would be possible/useful to store the 
> simplified feature within the database. This would then allow the user to 
> specify which 'version' of a spatial dataset should be retrieved. This would 
> provide a similar functionality as is already available for raster datasets 
> where pyramids are used to provide this functionality. What does the rest of 
> you think about this?
> 
> Christoph
> 
> 
> On Thursday 28 August 2003 04:29 pm, Martin Davis wrote:
> > > of self-intersection when you process a polygon. So why not put it in as
> > > an method that is only a member of LineString / MultiLineString class ?
> >
> > If we were putting D-P into JTS, that would be one place to put it,
> > alright.  However, as I said I'd really rather keep JTS focussed on core
> > algorithms.
> >
> > On a philosophical note, adding algorithms as methods to Geometry objects
> > seems to be encouraged by the OO paradigm, but it's not the most scalable
> > or flexible way of doing things.  For algorithms such as D-P which are
> > pretty independent of the internal representation of the Geometry I think
> > it's nicer to keep them outside the Geometry class in a separate algorithm
> > class.
> >
> > Martin Davis, Senior Technical Architect
> > Vivid Solutions Inc.
> > Suite #1A-2328 Government Street   Victoria, B.C.   V8T 5G5
> > Phone: (250) 385 6040    Fax: (250) 385 6046
> > EMail: mbdavis at vividsolutions.com  Web: www.vividsolutions.com
> >
> 
> 
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