QUOTE (peter59 @ Jul 14 2007, 09:48 PM)
![*](http://www.unmannedspaceflight.com/style_images/ip.boardpr/post_snapback.gif)
with ugly artifacts (for example, image 1204, see left top and left
bottom corners).
Are you sure the IMG software you're using is handling the IMGs correctly? What you've shown is a classic case of digital number (DN) clipping back to zero. This can happen if the software incorrectly assumes incorrect valid ranges representing brightness - note that only the brightest areas are clipped.