Nice to know that gdal_calc works fine ;) I work a lot with gdal + numpy, even for custom tools, and I admit they work very well together!
2014-11-19 11:41 GMT+01:00 Andreas Neumann <[email protected]>: > Hi, > > I will have to do further testing about GRASS. On Windows (OSGeo4W > install) it does not work too well. It probably works better on Linux. > > The gdal_calc.py solution works very fast though - glad that we came to > this solution! > > Andreas > > > On 19.11.2014 11:25, G. Allegri wrote: > > 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 <[email protected]>: > >> 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] >>> >>> >> >>> >> [email protected] >>> >> +34 699.680.261 >>> >> >>> >> 2014-11-19 9:05 GMT+01:00 Andreas Neumann <[email protected]>: >>> >> >>> >>> 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 >>> >>> [email protected] >>> >>> http://lists.osgeo.org/mailman/listinfo/qgis-developer [4] [1] >>> >> >>> >> _______________________________________________ >>> >> Qgis-developer mailing list >>> >> [email protected] >>> >> 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 >>> > [email protected] >>> > 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 > > > -- 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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