DOCBOOK-APPS: Images and pdf again

Hi all,

I've been searching through the archives of the list, found some threads
about images for PDF, but nothing solving my problem:

first of all, resizing of images does not work. Using that:
<imagedata fileref="image.gif" format="gif" width="3in" scalefit="1">
has strictly no effect on the rendered size of the image.

Secondly, I've read that one may use the epdf format, but which
format="" option should I use? The list of supported formats does not
include EPDF.

My problem is that I have high res images for which I don't want to
perform a resizing, just change the resolution as in EPS files for
postscript output.

Thanks, Camille.