[GRASS-user] Map Collars

Markus Neteler neteler at osgeo.org
Mon Mar 16 10:01:37 EDT 2009

On Mon, Mar 16, 2009 at 1:45 PM, Chris h <chris123 at magma.ca> wrote:
> Greets:
> New to grass and just finished building the latest release. What I would like
> to accomplish is a simple personal project and that is to stitch together the
> NOAA Raster charts for the Eastern Seaboard then tile them up and make them
> available via a wms server to feed and open source nagivation app gpsdrive.
> The first issue to tackle is to remove the collars of the NOAA charts. I've
> searched the archives and there are only two dated posts and both recommend
> shapefiles. Well there are no shapefiles for the Atlantic or other water
> bodies so this method cannot work.
> If anyone has any suggestions or ideas it would be greatly appreciated on how
> to remove map collars of NOAA charts.

Could you point us to a sample map?

WIth r.in.poly you could "digitize" the area of interest, then use
r.mask to remove the outside area, then r.patch everything.
With a small script you could generate the ASCII polygon file
for r.in.poly based on the map extent.


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