[GRASS-user] flip raster

[Nikos Alexandris]

On Tue, 2008-10-07 at 01:37 +0100, Glynn Clements wrote:
> José María Michia wrote:
> 
> > I've imported a NetCDF file (ETOPO1 model). The resulted raster appears
> > flipped vertically. How can I fix this? I try with mapcalc, without success:
> > 
> > - neighborhood modifier: not accept computations in offset parameter, like
> > map[0,total_rows-row()]
> > - I dont know how to query map in arbitrary coordinates, like
> > map(x(),-1*y())
> 
> There isn't any mechanism in r.mapcalc to achieve this. I'm not sure
> that it's possible to do it entirely within GRASS. Flipping
> geo-referenced data doesn't really make much sense.
> 
> Either figure out how to import it with the correct orientation, or
> export it, flip the exported data, then re-import.

Glynn and All,

excuse me for hijacking the post. I am looking for a way (just for the
fun of the game or for philosophical re-search) to rotate geotiffs at
180 degrees (i.e. flip vertically and horizontally). I've posted about
this in the gdal-dev list [1].

Is there a way to accomplish a 180 deg. rotation using the
listgeo/geotifcp command line tools?

Thank you, Nikos

[1] http://lists.osgeo.org/pipermail/gdal-dev/2008-October/018548.html