Printing, pre-press, publishing and photography services – yesterday, today and tomorrow

Contents:

1. Digital Magic
2. Painting By Numbers
3. A Revealing Image
4. As Easy as Calling Up a Log
5. A Lunar Odyssey
6. Fun with Fuzzy Filters
7. Building Color
8. A Digital Toolbox

A Revealing Image

Your friends are well into their evening of image processing. Now he's scanning the crosshair over the image looking at pixel values beyond the outermost turn in the spiral arms. "The sky background far away from the galaxy has a pixel value of about 210, but you can see the areas just outside the image are brighter than the sky - they run 230 or so. That means there's stuff out there we can't yet see. That's what I want to get."

They consult momentarily. Terms like "gamma" and "log" pass between them. They've made a decision. He clicks the mouse on a menu, selects Log, and the image changes dramatically. She turns to you and whispers, "I still can't get over how much faint stuff surrounds galaxies. In all the years we did photography, we never got negatives that showed the spiral arms anything like this. I just love it."