Are .ovr files just tifs with a different file extension? If so, could you use, gdalwarp -tr # # -r lanczos output.ovr?
Eli On Mon, Nov 28, 2011 at 10:57 PM, Chaitanya kumar CH <chaitanya...@gmail.com> wrote: > Robb, > > Note that the quality is effected by the levels you choose. > Can you provide a small part of the image where the overview is garbled the > most. > > > On Tue, Nov 29, 2011 at 12:00 PM, Robb Wright <robbkwri...@gmail.com> wrote: >> >> Thanks Chaitanya. Unfortunately gdaladdo doesn't support the Lanczos >> resampling type. Lanczos creates - by far - the best looking downsampled >> images for my type of rasters. What I'm looking for is a way to create >> pyramid layers/.ovr files using the Lanczos resampling method. >> >> Robb >> >> >> On 11/29/2011 12:58 AM, Chaitanya kumar CH wrote: >> >> Robb, >> >> If you are using gdal version 1.6 or later, you can use the -ro option[1]. >> It opens the tiff file in read-only mode and creates external overview. >> >> [1]: http://www.gdal.org/gdaladdo.html >> >> On Mon, Nov 28, 2011 at 11:53 PM, Robb Wright <robbkwri...@gmail.com> >> wrote: >>> >>> >>> I'm working with indexed color types of raster data (charts). The data >>> is in RGB geotiffs and I'm using gdaladdo to create pyramid layers for them. >>> Unfortunately, the best method for this raster type available using >>> gdaladdo is still pretty bad - much of the linework becomes garbled when >>> viewing the pyramids. The best-looking method that I've been able to come >>> up with is: >>> gdaladdo.exe --config COMPRESS_OVERVIEW DEFLATE -r average >>> >>> The Lanczos algorithm method works beautifully when used with other >>> programs - but I need to create .ovr files. gdal_retile.py output looks >>> great - but I can't figure out how to create .ovr files from that output. >>> >>> Does anybody know of the availability of the Lanczos resampling method >>> for gdaladdo - or of another way to create .ovr files with Lanczos? >>> >>> Robb >>> _______________________________________________ >>> gdal-dev mailing list >>> gdal-dev@lists.osgeo.org >>> http://lists.osgeo.org/mailman/listinfo/gdal-dev >> >> >> >> >> -- >> Best regards, >> Chaitanya kumar CH. >> >> +91-9494447584 >> 17.2416N 80.1426E >> >> > > > > -- > Best regards, > Chaitanya kumar CH. > > +91-9494447584 > 17.2416N 80.1426E > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev