JPEG -- how do I display one?

["Charles Packer" <mailbox cpacker org>]

The GTK mailing list archive search engine is broken, so I 
don't know if this topic has been covered before:

I would like to use ImageMagick functions to manipulate
pixel images and then display them under GTK. Problem is,
ImageMagick documentation has nothing about how to interface
to any kind of GUI environment, and GTK documentation that I've
been able to find so far has nothing about how to interface
with standard image formats. 

If somebody could point me to example code on how to read in
an image file -- JPEG or PNG24, say -- and display it, I could take it
from there.