Martin, You could scale the actual values into 'float' values between 0 and 255. This way you can still have the resolution. Conversion to 8-bit will be easier.
Use GDALRasterBand::GetOffset() and GDALRasterBand::GetScale() along with GDALRasterBand::SetOffset() and GDALRasterBand::SetScale() Docs at http://gdal.org/classGDALRasterBand.html describe how to use these. On Tue, Aug 10, 2010 at 4:32 PM, Andrew Brooks <a...@sat.dundee.ac.uk> wrote: > On Tue, 10 Aug 2010 11:46:00 +0100, Martin Raspaud <martin.rasp...@smhi.se> > wrote: > >> We have a satellite image in black and white, which show IR brightness >> temperatures. The data is scaled between 0 and 255 for viewing, and this >> is >> packed in a geotiff file >> >> Now some users would like to have the true value of the brightness >> temperature >> embedded in the file also. >> > > Maybe you can simulate something close by putting a scale and offset (slope > and intercept) into the geotiff so you still display 8-bit values but a > decent > image viewer will also calculate the true values and give a pixel readout > of > the true value under the cursor. I say simulate because 8 bits may not give > sufficient resolution. > > Andrew > > _______________________________________________ > gdal-dev mailing list > gdal-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/gdal-dev > -- Best regards, Chaitanya kumar CH. /tʃaɪθənjə/ /kʊmɑr/ +91-9494447584 17.2416N 80.1426E
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