Selon Otto Dassau <[email protected]>: > Hi, > > fowarded from grass list, because it is probably better here with some > additional notes: > > I used Float32 as data type for the export to ERDAS Img, so the data a > floating point and there is a color table but the colortable does not reflect > the floating point data. > > Color Table (RGB with 174 entries) > 0: 0,191,191,255 > 1: 58,151,105,255 > 2: 59,152,105,255 > 3: 60,153,105,255 > 4: 61,154,105,255 > 5: 62,155,104,255 > 6: 64,156,104,255 > > Is it possible somehow to adjust the colortable after the GRASS export to get > a color table that distinguishes floating point values as it does in GRASS?
Otto, In the GDAL data model, the index of a color table is necessary a (positive) integer. So there's no direct way to translate the GRASS color table of a floating point band into a matching GDAL object. There are several workarounds you could try : * put your color table in a text file that can be used for example by "gdaldem color-relief" . See http://gdal.org/gdaldem.html * build a Raster Attribute Table from the color table and set it to the IMG dataset. But be aware that R.A.T. are rarely exploited by GDAL utilities. Best regards, Even > > thanks a lot > Otto > > Am Fri, 22 Jul 2011 09:18:53 +0200 > schrieb Otto Dassau <[email protected]>: > > > Hi, > > > > I have an elevation map in GRASS with a color table that distinguishes > > decimal values based on the srtm color table, see below. I only want to > > have the value 0 in aqua, and all values <> 0 shall reflect land below or > > above sea level. > > > > -10 57 151 105 > > -0.000001 57 151 105 > > 0 aqua > > 0.000001 57 151 105 > > 50 117 194 93 > > 100 230 230 128 > > 200 202 158 75 > > > > When I export the raster with r.out.gdal (nor now I used GeoTiff and ERDAS > > Img) the color table seems to be changed to reflect "only" integer values. > > so all 0 floating point values are displayed as aqua. > > > > Is there a solution for this? > > > > Thanks a lot > > Otto > > > > > _______________________________________________ > gdal-dev mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/gdal-dev > _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
