How to scale image so it will fit on a PDF page while conserving the initial ratio?

Hi,

How to scale image so it will fit on a PDF page while conserving the initial ratio?
The original size of the image that I scaled is 1152 width x100 height.
After reading this web page http://www.sagehill.net/docbookxsl/ImageSizing.html, 
I have put the following attributes:
<imagedata contentdepth="100%" fileref="HugeWidth.bmp" scalefit="1" width="100%" />

The newly created image in the generated PDF file doesn't have the same ratio as the original.
Tools used:
   -xsltproc.exe
   -FOP 0.91Beta
   -Docbook-xsl v1.69.1

Can some1 help!
Thx!

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com