[xsl] removing watermark in a post process

[Geert Bormans <geert@xxxxxxxxxxxxxxxxxxx>]

Hi all,

I have added a watermark to my PDF books, stating it is a draft.
The PDF comes from part lists and it takes a while to get them 
processed using FOP.
I am generating multiple language books from the same (long) part list
If there are no changes required, the book status can go from "draft" 
to "release" just like that
So my customer wants to post process the resulting PDF to remove the 
"draft" image,
without running the FOP process again, hoping this would be a faster process

I am not sure on how I can get this to work.
It is one draft.jpg that is a background image and referenced a lot in the FO

Any suggestions?

Thanks in advance

Geert