DOCBOOK: Image scaling issues with DocBook

[Ben Rockwood <BRockwood@homestead-inc.com>]

Hello.

I've recently started using DocBook (using OpenJade and teTeX) and
been very pleased, however I've run into some problems when it comes
to images.

Firstly, when images are used, is there a way I can make sure they 
are centered on the output page (of either html or pdf)?  I doesn't
look very pro when they are aligned to the left.

Secondly, and more importantly, my images aren't scaling.  Is there
a way to ensure that my images are scaled appropirately for the output?
The default images look fine in the HTML output, but when I output PDF
or PS the images absorb an entire page and they still "fall off the page"
(meaning the image gets cut off because it exceeds the right side of the PDF page)  I'm using PNGs as the image format.  

Any ideas?  I've been using both the docbook.dsl and ldp.dsl.

brockwood@homestead-inc.com