thanks Hanlie. cleo
On Fri, Aug 22, 2014 at 9:01 PM, Hanlie Pretorius < [email protected]> wrote: > Hi Cleo, > > I used > > -scale 0 4095 0 255 > > The reason for the 4095 is that the images actually use only the first > 12 bits of the 16 bits (according to the documentation) and 2^12 = > 4096. > > If it was a true 16 bit image I would use 65535 for the 'max from' value. > > Regards > Hanlie > > > > 2014-08-22 13:56 MGT+02:00, Cleo Drakos <[email protected]>: > > hi Hanlie, > > can you tell me what value you put for -scale to convert into 8 bit? > > > > cleo > > > > > > On Fri, Aug 22, 2014 at 7:02 PM, Hanlie Pretorius < > > [email protected]> wrote: > > > >> Hi Even, > >> > >> Yes, I quoted the exact message, but it displays in the QGIS interface. > >> > >> I tried gdal_translate with the -ot and -scale parameters on the > >> multispectral image and that worked much better, thanks. > >> > >> Regards > >> Hanlie > >> > >> 2014-08-21 20:33 MGT+02:00, Even Rouault <[email protected]>: > >> > Le jeudi 21 août 2014 08:57:32, Hanlie Pretorius a écrit : > >> >> Hi, > >> >> > >> >> I'm working with a 16 bit SPOT 6 image that I want to convert from 16 > >> >> bit pixel depth to 8 bit pixel depth. I say 16 bit, but if I load the > >> >> file into Envi, it reports that uses only 12 bits. However gdalinfo > >> >> reports 16 bit (see below). > >> >> > >> >> I've manage to do so on the multispectral image, but the result is > >> >> poor colour wise. > >> >> > >> >> So I split the image into its four bands that is, I now have one > image > >> >> per > >> >> band. > >> >> > >> >> When I now try to convert to 8 bit, I get a message that says: > >> >> "Warning 742327101_R1C1_band1_8bit.TIF not created". > >> > > >> > Are you quoting the exact message ? I can't find any trace of it in > the > >> > relevant parts of the source code. Did you check that you have write > >> > permissions in the directory where you launch the command ? > >> > > >> > Anyway for what you want to do you likely need to explore the -scale > >> option > >> > of > >> > gdal_translate. But that's unrelated to the error > >> > > >> >> > >> _______________________________________________ > >> gdal-dev mailing list > >> [email protected] > >> http://lists.osgeo.org/mailman/listinfo/gdal-dev > >> > > >
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