[gdal-dev] gdal contour, output polygon

[Jamie Adams]

You could also try using
gdal_polygonize<http://www.gdal.org/gdal_polygonize.html>,
but you'd need to find a way to reclass your source raster to discrete
groups (i.e, elevation ranges).  This could be done pretty easily using
python, maybe something like
val_repl.py<https://svn.osgeo.org/gdal/trunk/gdal/swig/python/samples/val_repl.py>.


-Jamie

On Wed, Mar 11, 2009 at 12:56 PM, ValiSystem <vali.system at free.fr> wrote:

> Hello !
>
> I'm trying to generate polygons from gdal contour output. Most of the
> linestrings generated where closed, so it's not a too bad start. The problem
> is to define interior and exterior of the polygon : it seems that interior
> and exterior has no consistent meaning from the linestrings (it makes sense
> though - a line has no interior nor than exterior).
>
> So what i need would be a method to recreate the meaning of the polygon :
> the inside is where i have ground. To make it work, i just would have to
> transform the polygon to an interior ring of a wider (whole area) polygon
> when appropriate (when it does not contain a polygon with a higher
> altitude).
>
> What do you think about this ? is there a better/known way to achieve that
> ?
>
> _______________________________________________
> gdal-dev mailing list
> gdal-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/gdal-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/gdal-dev/attachments/20090312/5e135ec2/attachment.html