Patrick, You have single handedly taught me more about image processing than any of my books. On the other hand you have been producing data so fast I haven’t had time to read any of my books. Lest that sounded like a complaint I do want to thank you again for the fun time learning about image processing. Like Roger I keep most of my booboos to myself. We could all learn faster if someone would look at our images and say, “why don’t you try this?” Or maybe something like this – Joe said, “Here's my slapdash effort to assemble Patrick's data…” Joe, I worked a long time trying to do what you did and couldn’t. How did you lighten the Horse Head background with out loosing the dark color in the Horse Head itself? You did something besides curves I am guessing. Here’s what I came up with for Patrick’s mosaic. http://www.slas.us/gallery2/main.php?g2_itemId=1147 Jim