Hi Cathal,
Ok, now I can reproduce this. In fact, it is a "feature" that applies to the original image also. Here is a snippet of source:
/* swap dark-bright color map.
?* this is used to keep mountains looking like mountains when flipping t/b
?*/
static void
swap_colors()
?
For the original image, to my eye at least, when the image is flipped top/bottom the shadows make the craters look like mountains and vv. I've always had this inversion of relief, it's especially bad with lunar images.
To remove this feature, the simplest thing to do is just add a return as the first statement in this function so it does nothing.
Elwood
