Andreas, >it turns out that all pixel values with 255 are now nodata values ;-( Is >there an option so that my 255 values are not turned into nodata? I >tested with the --NoDataValue option (e.g. 99 - which I don't use in the >image), but it seems to be ignored. For me it is important that black >and white pixels are preserved.
I submitted a patch to help with this sort of thing to the GDAL team 17 months ago which is unfortunately being blocked/ignored longterm for (what I consider to be) very unwise reasons. https://trac.osgeo.org/gdal/ticket/5130 In the meantime I suggest you can download this alternative version that will give you full control over how nodata in controlled across multiple rasters. It's only a couple of lines patched from the original version. We use it on national scale rasters here with very complex functions, but it works just as well for easy functions. https://github.com/gbb/gbb_gdal_calc Graeme. _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
