I agree that unsigned byte does not support -128. Signed byte does support -127. Signed byte does not could support -128. I note that http://www.gdal.org/gdal_translate.html shows that gdal_translate supports 11 data types Byte/Int16/UInt16/UInt32/Int32/Float32/Float64/CInt16/CInt32/CFloat32/CFloat64, and "Byte" is included, but I think this "Byte" refers to unsigned byte. I do not see any indication that gdal_translate supports signed byte. Greg
On Aug 6, 2010, at 12:23 PM, Even Rouault wrote: > Filippo, > > What is the format of that raster file ? Can you share a link to the dataset > ? > or the output of gdalinfo at the very least > > I'd note that -128 can only be considered a valid value for a 8bit raster if > the metadata item PIXELTYPE at band level is set to SIGNEDBYTE > (IMAGE_STRUCTURE metadata domain). > > Best regards, > > Even > > Le vendredi 06 août 2010 18:08:56, Filippo Corò a écrit : >> Hi List, >> >> I have a problem with the function GetNoDataValue () of GDAL 1.6.2 ver. I >> use some raster where the nodatavalue is equal to -128 and the pixel depth >> is 8bit. Opening the raster with the following code (with pydev end >> python 2.6): >> >> # Get the bands and block sizes >> primoBand primoDs.GetRasterBand = (1) >> noval primoBand.GetNoDataValue = () >> >> Get noval = 0.0 and not -128 as I expected. >> Is there any option I can use to solve the problem? >> >> Thanks in Advance >> >> Greetings >> Filippo Corò _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
