Hi, Resampling is science that would be nice to understand. Unfortunately I don't but I think that this thread is worth reading osgeo-org.1560.x6.nabble.com/gdal-dev-downsampling-geotiff-with-a-low-pass-filter-td5385890.html. In this gis.SE question cubic spline was considered good https://gis.stackexchange.com/questions/30627/smoothing-reinterpolating-raster-with-gdal.
-Jukka- -----Alkuperäinen viesti----- Lähettäjä: Stephen Woodbridge <stephenwoodbridg...@gmail.com> Lähetetty: torstai 20. elokuuta 2020 16.58 Vastaanottaja: Rahkonen Jukka (MML) <jukka.rahko...@maanmittauslaitos.fi> Aihe: Re: [gdal-dev] I have a problem getting higher resolution in a VRT file Hi Jukka, Any thoughts on what would be a better way to upsample and image using GDAL? I assumed, maybe incorrectly, that if I’m up sampling between two pixels with values of say 1 and 2 that a new pixel 50% between them would get a value of 1.5 and at 25% would get a value 1.25 etc. using linear interpolation and bilinear would also account for rows above and below the current row. Even, I specified resampling=“bilinear” in the vrt file is this ignored? Thanks, Steve Sent from my iPhone > On Aug 20, 2020, at 8:23 AM, jratike80 <jukka.rahko...@maanmittauslaitos.fi> > wrote: > > Even Rouault-2 wrote >> ... >> By default, VRT uses nearest resampling. You must specify something else. >> Look for "A resampling attribute can be specified" in >> https://gdal.org/drivers/raster/vrt.html >> ... >> >> -- > > Actually in the provided .vrt file I can see <SimpleSource > resample="bilinear"> > > But isn't bilinear unsuitable for upsampling and some more blurring > method might work better? > > -Jukka Rahkonen- > > > > -- > Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev