This page is a Recipe-book for people who are dealing with images. These are mostly for experts, so they're very brief descriptions. If you don't understand what is written here, you probably don't need to know. None of these recipes are "the only way to do it" or even necessarily the best way to do it, they're just techniques that other DPers have found useful.
Removing Halftone screen
These are recipes for dealing with the small dots (a lot like pixels in a monitor) that occur in photos in printed material.
- piggy's method: I scan most photographs at 1200ppi. I measure the dot center to dot center, motion blur by that along a 45 degree axis, and then 135 degrees, and then half that along 270 degrees. That's a nice starting image for additional work. For bulk descreening, I use peiHalfTone, though many folks have difficulty getting this application to build properly.
- Donovan's method: I find an RLE blur of radius dot-center-to-neighbor-dot-edge gives very good results, if followed by a single pixel linear blur.