The response I got to a similar Q worked well. Maybe it would
be the answer for you. My Q was
Subj. Removing lines from scanned image.
The suggestion I got was
Try Image->Filters->Colors->Color to Alpha to remove the white
> I search for a gimp plugin or a program under linux to remove the grid
> from a scanned image. (It would be great also find a automatically
> rotate tool.)
> It is anybody there who have a bit experience to scan images?
> Best regards,
> GPG-kulcs: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x783AA8D8 >
> BodyID:435416.2.n.logpart (stored separately)