Hi PIE.
No, there is no up and down but that is different than mirror image. You can't fix a mirror image just by rotating it 180 degrees. That never works.
You can't rotate your right-hand palm facing you 180 degrees (or any other degrees) to look like your left-hand palm facing you. That is because they are mirror images, not just rotated.
My images are the proper orientation before they get to GraXpert per all the star charts and then GraXpert does a mirror image flip.
Thanks,
Paul
You didn't say Mirror image. You said top to bottom. 
Anyway, if it is how you like it, why use GraXpert?
What if you run it through GraXpert twice?
1st run comes out upside down,
Second run comes out right side up.

I'm a post processing minimalist. No smoke and no mirrors.
And why I use a rotator. Frames up the image the way I want to see it.
(Because, we will never see it in person.)
