[plt-scheme] image manipulation library?

Hello all,

Have been updating my scripts to work with version 3.00 (paths threw a
wrench in the works), and am now continuing with my present pet
project, which brings me to my next question.  Is there a library for
manipulating images (pretty basic stuff, mostly resizing jpgs and maybe
converting them to png format)?

I know that Dr. Scheme has native support for images, but that seems to
be a different thing.  I can always call out image magick through the
shell (I guess I could use the ffi to use the library directly, but
time is limited and I have other things to learn before the ffi).

Any suggestions would be welcome and thanks in advance for the help.

Rohan