Has anyone looked into the so called regrid in Earth system model? How is it different from GIS resampling?
Grid Remapping ESMF has the option to build a standalone application, called *RegridWeightGen <http://www.earthsystemcog.org/projects/regridweightgen>*, that can generate interpolation weights in parallel. It's fast and can handle a wide variety of grids and grid options. It's not necessary to use the rest of ESMF to use it ... just provide grid files in a standard (netCDF-based) format. https://www.earthsystemcog.org/projects/esmf/ Thanks. On Thu, Aug 20, 2020 at 8:40 AM Stephen Woodbridge < stephenwoodbridg...@gmail.com> wrote: > Jukka, > > > > Thanks those are great threads and very educational. > > I solved my problem. I was using upsample="bilinear" rather than > > upsampling="bilinear" and fixing this gave the expected results. But if > > not for my stupid typo, I would not have had a chance to read those > > threads and google others regarding upsampling. > > > > Thanks for the assist, > > -Steve > > > > On 8/20/2020 10:13 AM, Rahkonen Jukka (MML) wrote: > > > 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 -- Best Regards! Chang Liao,PhD Earth Scientist, Atmospheric Sciences & Global Change Division Pacific Northwest National Laboratory, WA, USA. Email: changliao.climate at gmail.com or chang.liao at pnnl.gov Personal Website: http://www.changliao.us Skype: changliao1025 Lab Website: www.pnnl.gov
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