Le mercredi 24 juin 2015 03:49:15, Stephen Woodbridge a écrit : > Hi All, > > I have a geotiff file like: > > [] ~/work/oceandata/test$ gdalinfo A2015173174000.L0_LAC.L2_OC.tif -noct > Driver: GTiff/GeoTIFF > Files: A2015173174000.L0_LAC.L2_OC.tif > A2015173174000.L0_LAC.L2_OC.tif.aux.xml > Size is 2433, 1727 > Coordinate System is: > GEOGCS["WGS 84", > DATUM["WGS_1984", > SPHEROID["WGS 84",6378137,298.257223563, > AUTHORITY["EPSG","7030"]], > AUTHORITY["EPSG","6326"]], > PRIMEM["Greenwich",0], > UNIT["degree",0.0174532925199433], > AUTHORITY["EPSG","4326"]] > Origin = (-84.000000000000000,45.000000000000000) > Pixel Size = (0.012741471640766,-0.012738853693008) > Metadata: > AREA_OR_POINT=Area > Image Structure Metadata: > INTERLEAVE=BAND > Corner Coordinates: > Upper Left ( -84.0000000, 45.0000000) ( 84d 0' 0.00"W, 45d 0' 0.00"N) > Lower Left ( -84.0000000, 22.9999997) ( 84d 0' 0.00"W, 23d 0' 0.00"N) > Upper Right ( -52.9999995, 45.0000000) ( 53d 0' 0.00"W, 45d 0' 0.00"N) > Lower Right ( -52.9999995, 22.9999997) ( 53d 0' 0.00"W, 23d 0' 0.00"N) > Center ( -68.4999997, 33.9999998) ( 68d30' 0.00"W, 34d 0' 0.00"N) > Band 1 Block=2433x3 Type=Byte, ColorInterp=Palette > Min=0.000 Max=250.000 > Minimum=0.000, Maximum=250.000, Mean=0.850, StdDev=9.542 > Metadata: > STATISTICS_MAXIMUM=250 > STATISTICS_MEAN=0.85033548789076 > STATISTICS_MINIMUM=0 > STATISTICS_STDDEV=9.542216344358 > Color Table (RGB with 256 entries) > > It has multiple entries to the color lookup table that should be treated > as NODATA for example entries 251-255. > > So I run gdal_calc.py like: > > [] ~/work/oceandata/test$ gdal_calc.py -A > A2015173174000.L0_LAC.L2_OC.tif --outfile=test.tif --calc="A*(A<251)" > --NoDataValue=0 --co="TILED=YES" > 0 .. 10 .. 20 .. 30 .. 40 .. 50 .. 60 .. 70 .. 80 .. 90 .. 100 - Done > > and it create a gray-scale image with no color lut. > > [] ~/work/oceandata/test$ gdalinfo test.tif > Driver: GTiff/GeoTIFF > Files: test.tif > Size is 2433, 1727 > Coordinate System is: > GEOGCS["WGS 84", > DATUM["WGS_1984", > SPHEROID["WGS 84",6378137,298.257223563, > AUTHORITY["EPSG","7030"]], > AUTHORITY["EPSG","6326"]], > PRIMEM["Greenwich",0], > UNIT["degree",0.0174532925199433], > AUTHORITY["EPSG","4326"]] > Origin = (-84.000000000000000,45.000000000000000) > Pixel Size = (0.012741471640766,-0.012738853693008) > Metadata: > AREA_OR_POINT=Area > Image Structure Metadata: > INTERLEAVE=BAND > Corner Coordinates: > Upper Left ( -84.0000000, 45.0000000) ( 84d 0' 0.00"W, 45d 0' 0.00"N) > Lower Left ( -84.0000000, 22.9999997) ( 84d 0' 0.00"W, 23d 0' 0.00"N) > Upper Right ( -52.9999995, 45.0000000) ( 53d 0' 0.00"W, 45d 0' 0.00"N) > Lower Right ( -52.9999995, 22.9999997) ( 53d 0' 0.00"W, 23d 0' 0.00"N) > Center ( -68.4999997, 33.9999998) ( 68d30' 0.00"W, 34d 0' 0.00"N) > Band 1 Block=256x256 Type=Byte, ColorInterp=Gray > NoData Value=0 > > > [] ~/work/oceandata/test$ gdalinfo --version > GDAL 1.10.1, released 2013/08/26 > > So is there away to get gdal_calc.py to copy the LUT to the output file? > Is there a better way/different way to set these pixels to be NODATA?
Steve, https://svn.osgeo.org/gdal/trunk/gdal/swig/python/samples/attachpct.py could be used as post processing to re-apply the color table. Even > > Thanks, > -Steve > _______________________________________________ > 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
