How to resize & scroll image within a fixed region on iPad's Safari?

Question

There are very good demos show a fixed header on top & scrollable contents below in mobile Safari(see: cubiq.org/dropbox/iphonescroll.html & doctyper.com/stuff/iphone/fixed/). But if we also want to scale image around within lower part. How can we do this?

Answer 1

I found the solution with the help of code from Alex Gibson. But it's not smoothy as Safari does. I'll try to solve this performance problem.