Because many of you probably are quite familiar with photo editing soft ware I hope you will please forgive me putting a technical question to /p/.

I have split a few thousand images into three separate images each (the top 1 middle 2 and bottom 3). These blocks all have the same resolution (480X320)

What I need to do is rejoin the images edge to edge in the order of the bottom panel on the right, the middle panel in the middle, and the top panel on the far left.

It is an unusual thing to batch and so I am a little stumped on how to do it in any thing but just paint and copy/paste thousands of times.