Hi Ian, I believe in practice we could consider expanding to RGB before we do affine/warp operations against indexed color model images, during rendering, that might provide better output (in theory).
At some point it was actually done (at least in part, I don't recall the details), but it was causing other issues: https://osgeo-org.atlassian.net/browse/GEOT-6180 Given dedicated funding, we could research a different way of working on color mapped images, that would allow for improved quality output without incurring in the issues reported in GEOT-6180. Cheers Andrea On Sun, Jan 19, 2020 at 12:22 PM Ian Turton <ijtur...@gmail.com> wrote: > > That is the expected behaviour with a paletted image, the values of two > neighbouring pixels have no relationship to each other so any form of > averaging is going to produce a wrong result. > > You could convert them to be RGB images using GDAL (pct2rgb.py) but they > will still look a bit mushy when you average them. > > Ian > > On Sat, 18 Jan 2020 at 17:11, Russ Hore <r...@russ-hore.co.uk> wrote: > >> I have an issue if I set the WMS default interpolation to anything other >> than “Nearest neighbour” and zoom in. >> >> OS : Ubuntu 19.01 >> >> >> If I set the interpolation to Bilinear or Bicubic, at the same zoom level >> I see; >> >> >> >> The back end tiles are generated from TIFF files using; >> >> gdalbuildvrt -a_srs EPSG:27700 outfile.vrt *tif >> gdal_translate -of GTiff -r nearest -a_srs EPSG:27700 outfile.vrt >> mergedfile.tif >> >> >> >> _______________________________________________ >> Geoserver-users mailing list >> >> Please make sure you read the following two resources before posting to >> this list: >> - Earning your support instead of buying it, but Ian Turton: >> http://www.ianturton.com/talks/foss4g.html#/ >> - The GeoServer user list posting guidelines: >> http://geoserver.org/comm/userlist-guidelines.html >> >> If you want to request a feature or an improvement, also see this: >> https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer >> >> >> Geoserver-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/geoserver-users >> > > > > -- > Ian Turton > _______________________________________________ > Geoserver-users mailing list > > Please make sure you read the following two resources before posting to > this list: > - Earning your support instead of buying it, but Ian Turton: > http://www.ianturton.com/talks/foss4g.html#/ > - The GeoServer user list posting guidelines: > http://geoserver.org/comm/userlist-guidelines.html > > If you want to request a feature or an improvement, also see this: > https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer > > > Geoserver-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/geoserver-users > -- Regards, Andrea Aime == GeoServer Professional Services from the experts! Visit http://goo.gl/it488V for more information. == Ing. Andrea Aime @geowolf Technical Lead GeoSolutions S.A.S. Via di Montramito 3/A 55054 Massarosa (LU) phone: +39 0584 962313 fax: +39 0584 1660272 mob: +39 339 8844549 http://www.geo-solutions.it http://twitter.com/geosolutions_it ------------------------------------------------------- *Con riferimento alla normativa sul trattamento dei dati personali (Reg. UE 2016/679 - Regolamento generale sulla protezione dei dati “GDPR”), si precisa che ogni circostanza inerente alla presente email (il suo contenuto, gli eventuali allegati, etc.) è un dato la cui conoscenza è riservata al/i solo/i destinatario/i indicati dallo scrivente. Se il messaggio Le è giunto per errore, è tenuta/o a cancellarlo, ogni altra operazione è illecita. Le sarei comunque grato se potesse darmene notizia. This email is intended only for the person or entity to which it is addressed and may contain information that is privileged, confidential or otherwise protected from disclosure. We remind that - as provided by European Regulation 2016/679 “GDPR” - copying, dissemination or use of this e-mail or the information herein by anyone other than the intended recipient is prohibited. If you have received this email by mistake, please notify us immediately by telephone or e-mail.*
_______________________________________________ Geoserver-users mailing list Please make sure you read the following two resources before posting to this list: - Earning your support instead of buying it, but Ian Turton: http://www.ianturton.com/talks/foss4g.html#/ - The GeoServer user list posting guidelines: http://geoserver.org/comm/userlist-guidelines.html If you want to request a feature or an improvement, also see this: https://github.com/geoserver/geoserver/wiki/Successfully-requesting-and-integrating-new-features-and-improvements-in-GeoServer Geoserver-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/geoserver-users
