[GRASS-user] [GRASSLIST:1206] Re: rrd files and r.in.gdal

[sebastian sauer]

Fri 27 Jul 2007 16:13, Frank Warmerdam wrote:
> r.in.gdal does not exactly import overviews from any of it's input formats.
> However, GDAL does support overviews in Imagine files (.rrd files) so if
> you tried to import a big imagine files withoverviews into a low resolution
> location r.in.gdal would pull from an overview to speed up the import.

IMO this should make it into the otherwise excellent documentation.

http://www.gdal.org/frmt_hfa.html says regarding write support..

| If overviews are generated, they will be in an external .ovr (GeoTIFF
| file) recognised only by GDAL, not in the .rrd format produced by
| Imagine.

..so one might (wrongfully) believe there's also absolutly no read support 
for .rrd files.