BMP's (no not the armored personnel carriers :-) )
by Recluse
Yes indeed. That is how most of us make the MISSION and OBJECTIVE images.
Be advised, though, the default ALT-S .BMP (called DUMPxx.BMP where xx is a number in sequence) is a very large file and is the FULL SCREEN at whatever resolution you are running. You must usually crop and shrink the bitmaps to fit properly on the mission screens. See Baldeagle's tutorial on this in the Mission Builder FAQ section.