working with scanned pics: how to individually "chop up" pics

[Jeff C]

Hello,
I have used my scanner to scan 3 pics per scan. I didn't really care
if the pics were vertically and horizontally squared/aligned, because
I believe it's easy to edit it afterwards sing software like Gimp.

Is there a way for gimp, or ANY OTHER software easily available for
Ubuntu users, to quickly chop up the file into the 3 individual pics,
and to get them squared up (vertically and horizontally 90 degrees)? 
Thank you.


Please see my file at
http://snowflame.zoto.com/img/original/ddfd1b906271512faa623423632d3554.jpg

(I have covered up the people's faces for the privacy's sake)

Thank you.

jeff