Thanks for all the advice! I like the slicing into smaller tiles then combine with vrt approach.
On Wed, Jun 29, 2011 at 7:16 AM, Giuseppe Sucameli <[email protected]> wrote: > Hi all, > > On Jun 28, 2011, at 10:13 PM, Goyo <[email protected]> wrote: >> You can try gdaldem: http://www.gdal.org/gdaldem.html. You'll have to >> use the command line since it's not in the qgis raster plugin yet. > > wrong, it was implemented yet. > You can find it in GdalTools plugin since QGis 1.7, run Raster -> GdalDem. > You should be able to run it in QGis < 1.7, just enable experimental plugins > and update your GdalTools plugin. > > Cheers > >> I personally feel quite uncomfortable and experiment performance >> issues working with large rasters so this is what I do: >> >> - Keep my raster files small. I get almost all my DEMs from a WCS in >> 1000x1000 px tiles and convert them to 16 bit integers (they are 32 >> bits float originally but no DEM has so much precision). >> >> - Generate seperate hillshades for each DEM. The shaded relief plugin >> is very convenient and has the advantage of generating 128 bit >> rasters. >> >> - Avoid loading lots of rasters in a qgis project. Better combine them >> using VRT. I use it to combine dozens of DEMs when I need to cover >> larger regions in a single project with very good results. >> >> Goyo >> _______________________________________________ >> Qgis-user mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/qgis-user > > -- > Giuseppe Sucameli -- cheers, maning ------------------------------------------------------ "Freedom is still the most radical idea of all" -N.Branden wiki: http://esambale.wikispaces.com/ blog: http://epsg4253.wordpress.com/ ------------------------------------------------------ _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
