And do you have problems with GRASS (directly, not through Processing)? In GRASS7 you can even drectly write to Geotiff without passing through the internal format (http://grass.osgeo.org/grass70/manuals/r.external.out.html ). If GDAL is built with bigtiff support there souldn't be problems...
giovanni 2014-11-19 10:44 GMT+01:00 Andreas Neumann <a.neum...@carto.net>: > Hi Giovanni, > > I need to change all pixels that have the value of 249 to a value of 255. > All other pixels should stay at their value. > > Andreas > > Am 2014-11-19 10:21, schrieb G. Allegri: > >> From my grayscale tiff images I want to replace one pixel value >>> >> (249) with white (255). All other pixels should stay at the value they >> have. >> > >> > I came across https://github.com/chiatt/gdal_reclassify [1] - but >> this reclassifies all pixels, not only selected ones. >> > >> > Maybe I could use http://www.gdal.org/gdal_calc.html [2] with a >> conditional syntax? >> >> Hi Andreas, do you need to change the value of one specific pixel >> only? I mean the pixel at [x,y] index? >> >> giovanni >> >> >>> > Thanks, >> > Andreas >> > >> > Am 2014-11-19 09:10, schrieb Carlos López PSIG: >> >> >> >> Hi Andreas, >> >> >> >> I also had problems to reclassify BIGTIFF with SAGA and GRASS! >> >> Finally I used GDAL! >> >> >> >> Best regards, >> >> >> >> [2] >> >> >> >> CARLOS LÓPEZ QUINTANILLA >> >> >> >> www.psig.es [3] [2] >> >> >> >> >> carlos.lo...@psig.es >> >> +34 699.680.261 >> >> >> >> 2014-11-19 9:05 GMT+01:00 Andreas Neumann <a.neum...@carto.net>: >> >> >> >>> Hi, >> >>> >> >>> I tried various tools, e.g. >> >>> >> >>> * SAGA reclassify >> >>> * GRASS r.mapcalc >> >>> >> >>> Both work fine on smaller data sets, but fail on big data sets. >> >>> >> >>> This is on Win7 64bit, with the OSGeo4W installer. I have 8gb RAM >> >>> and 40GB disk free on C:, more free space on other disks where >> the >> >>> data resides. >> >>> >> >>> I am not totally sure if it is the Bigtiff issue or some other >> >>> issue. It is just a guess that maybe I am hitting a limit with >> tiff. >> >>> It is not fully transparent to me what Processing is doing in the >> >>> background (what file formats with what options it creates). >> >>> >> >>> It may also be an issue with SAGA or GRASS directly. >> >>> >> >>> Thanks if you know anything, >> >>> Andreas >> >>> >> >>> Am 2014-11-18 21:15, schrieb Giovanni Manghi: >> >>> >> >>> Hi, >> >>> >> >>> I am having a lot of troubles with large raster files and >> >>> processing. >> >>> >> >>> The intermediate results can go >4GB. Processing stops with not >> so >> >>> helpful error messages. >> >>> >> >>> I wonder if processing is hitting the 4GB limit. Can I force >> >>> processing >> >>> to use the BIGTIFF option or a raster format that can handle >4GB >> >>> files? >> >>> >> >>> Hi Andreas, what tool specifically? >> >>> >> >>> cheers >> >>> >> >>> -- Giovanni -- >> >>> _______________________________________________ >> >>> Qgis-developer mailing list >> >>> Qgis-developer@lists.osgeo.org >> >>> http://lists.osgeo.org/mailman/listinfo/qgis-developer [4] [1] >> >> >> >> _______________________________________________ >> >> Qgis-developer mailing list >> >> Qgis-developer@lists.osgeo.org >> >> http://lists.osgeo.org/mailman/listinfo/qgis-developer [4] [1] >> >> >> >> >> >> >> >> Links: >> >> ------ >> >> [1] http://lists.osgeo.org/mailman/listinfo/qgis-developer [4] >> >> [2] http://www.psig.es [3] >> > >> > _______________________________________________ >> > Qgis-developer mailing list >> > Qgis-developer@lists.osgeo.org >> > http://lists.osgeo.org/mailman/listinfo/qgis-developer [4] >> >> Links: >> ------ >> [1] https://github.com/chiatt/gdal_reclassify >> [2] http://www.gdal.org/gdal_calc.html >> [3] http://www.psig.es >> [4] http://lists.osgeo.org/mailman/listinfo/qgis-developer >> > -- Giovanni Allegri http://about.me/giovanniallegri Twitter: https://twitter.com/_giohappy_ blog: http://blog.spaziogis.it GEO+ geomatica in Italia http://bit.ly/GEOplus
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