[Gimp-user] Writing properties to images not possible?

[Irmhild Rogalla <irmhild rogalla institut-pi de>]

Hallo,

I'm new here and hope, that I get help.

My Gimp Version is 2.8.4-1 on Debian (unstable).

I want to add Creative Commons metadata (XMP) to my self created images 
(different data formats) and to export them as jpg (other formats are 
possible, but I prefer jpg).

But: Whenever I open the properties dialog and try to make some entries 
(e.g. title or import xmp) and save (as xcf) or export (as jpg) the 
image the data are lost.
At the first tries I can't choose the "save exif-data" or "save 
xmp-data" options at the advanced options dialog. But in the meantime I 
installed the exiftool, so it's possible to choose, but the result is 
the same: the data are lost.

What could I do?

        Irmhild