Need some Help

Ok, I've seen a lot of other maps with a pic from the game in the loading screen... but.. I still haven't figured out how to do it. I have a few maps that I wanted to do that with, but I also don't have a program that will let me see the photos... Unless I use windows multimedia, but then they show up upsidedown... What program do I need and how do I import the correct file?

Follow this tutorial to find out how to make a custom loading screen.
http://www.wc3campaigns.com/showthread.php?t=56751

GIMP is a good free program that can change the file type and view photos and such. Its under Files on the top of the page where UserCP is.