Anybody have a good formula to get rid of the half tone screen pattern from scanned photos from magazine and books?

Double the size & resolution you need then use the blur filter to minimize the dot pattern. Then reduce to final size & use the unsharp mask to sharpen it.

Also, sometimes scanners or scanner software will have a "descreen" feature, which essentially does the same thing, but it does it as it's scanning the photo.

In the end you can only use it if you are going to use the material smaller than the original for print purposes, otherwise you can get even wilder artefacts, called moirr when the new material will be rasterized again for full color printing. I never want to scan from print anymore, but sometimes you just have to. When it happens I start scanning at double the size (the tip from willf), that is slightly better than upping the resolution after scanning. Getting your hands on the original material that the magazine used is always better!

Attached Link: http://pdphoto.org/PictureHome.php?cid=12&mat=pdef&md=cid

I've always used descreen in my scanner software. It's not great, but it does help. As wilf says, scan at 300+ PPI and use gaussian blur to minimize the dot patterns. Unless, of course, you need to use the image at that size. I'd be cautious about using images from magazines though. If they're for personal use, you're okay, but if you use them commercially, there are copyright issues to deal with. May I recommend the URL above as a source for public domain royalty free stock images. There are other free stock image sources on the net too.

Attached Link: http://www.scantips.com

Thanks for all the fine tips. Here's a place I found after I wrote the question here. www.scantips.com I have to scan many copyright magazine images for work but there's a "Department of Copyright Okeydokey" that ask for permission. I just do the scanning.

If your company is going to go through the trouble of asking permission, it might be a good thing to go one step further and ask the magazine for a digital file of whatever page you need a copy of. It wouldn't be much trouble if they sent you copies of, say, the press-ready PDF files they sent to the printer. You'll get cleaner, sharper images that way.