Le mercredi 19 novembre 2014 14:16:05, Andreas Neumann a écrit : > Hi Even, > > Thank you for trying to help. Unfortunately, the --overwrite option does > not help. > > I have a very small test file at http://webgis.uster.ch/temp/test.tif > > I used the following options: > > gdal_calc.py -A test.tif --overwrite --outfile=testcalc.tif > --calc="(A==249)*255+(A<>249)*A" > > All pixels with values of "255" are now "nodata" after running gdal_calc > ;-(
I wrote "as well", so try with "--overwrite --nodata 99". > > May I please ask you to test/verify this? > > Thanks a lot! > > Andreas > > Am 2014-11-19 13:58, schrieb Even Rouault: > > Le mercredi 19 novembre 2014 13:49:48, Andreas Neumann a écrit : > >> Hi, > >> > >> I have an issue with gdal_calc.py and nodata values. > >> > >> My input data contains a lot of white pixels. After running > >> gdal_calc.py > >> with the following parameters > >> > >> gdal_calc.py -A test.tif --outfile=testcalc.tif > >> --calc="(A==249)*255+(A<>249)*A" > >> > >> it turns out that all pixel values with 255 are now nodata values ;-( > >> Is > >> there an option so that my 255 values are not turned into nodata? I > >> tested with the --NoDataValue option (e.g. 99 - which I don't use in > >> the > >> image), but it seems to be ignored. For me it is important that black > >> and white pixels are preserved. > > > > Use --overwrite as well, since otherwise the existing output file will > > be used > > to be just updated and not recreated. > > It would be appropriate that the utility warns that --NoDataValue has > > no effect > > when the output file exists. > > > >> Thanks for any hints, > >> Andreas > >> _______________________________________________ > >> gdal-dev mailing list > >> [email protected] > >> http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
