[gdal-dev] .ovr files and Lanczos
even.rouault at mines-paris.org
Tue Nov 29 13:43:30 EST 2011
Le mardi 29 novembre 2011 18:42:27, Eli Adam a écrit :
> Are .ovr files just tifs with a different file extension?
> If so, could you use, gdalwarp -tr # # -r lanczos output.ovr?
Yes, basically .ovr files are just tifs file (actually, I believe it could be
any raster type recognized by GDAL). There can have some special metadata for
particular cases like building overviews of 1-bit imagery (black&white), where
the result of the overview is 8-bit grey level to be nice-looking. But that's
However note that generally the resampling algorithm of gdalwarp have not been
coded to be applied to subsampling (they are adapted to reprojection where the
number of pixels isn't dramatically changed by the operation). So depending on
which one is used, the result might not be satisfactory.
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