So here's my project. My friend's b-day is coming up very soon and I want to make him a poster sized image (around 12x18, give or take) from a scan in an old book, a old fav of his. This is going to be run on either an Xerox iGen with a the latest version of DocuSP rip or an HP Indigo with the latest version of their rip software, both of which I operate and maintain. The problem I have, is that the halftone screen/rosettes are very noticeable.

I'm working with an Epson Perfection 2450 Photo scanner and will be using Photoshop CS2 for clean up. I'm pretty adept at Photoshop so I can most likely work through any more advanced advice.

I can take care of most of the solid color areas, but I'm stuck on fixing gradients and skin tone areas. Any ideas?

Moire is a pain. You might check out this tutorial at Magic Pixel (http://www.magicpixel.com.au/magicpixel/html/scan3a.html)

There are also some other tutorials there about scanning that may be of help. That describe rotation techniques when scanning.

Also check your Epson scanning software. You do have an option to turn on "Descreening" and that helps a lot. There are also third party plugins that can help. I use OnOne Software's Intellihance Pro's descreening function (after scanning with the Epson descreen option turned on and the quality set for "magazine")

Hiya --
i am new to this site ,and i am a time served high -end colour copier engineer ,we have customers with this problem day in day out ,it is not normally an issue in day to day copying ,but i work for companies that use machines that cost £40K and use them as a network printer/ scanner for marketing use .
Dont want to teach you to suck eggs ,but unfortunately moire is a very inexact science unless you know your input medium and your scanner intimately .
Firstly

have you tried the descreen button on the manual setting of the twain driver (only works in colour)--this is there for moire --:)

or Adjust the scan resolution by just a few pixels either way (yes you can type in non standard numbers !!)

or Move the image skew by a few milimeters then scan and correct later

or ,and not too many people know this, try putting a good quality transparency(OHP slide) between the image and the scan bed .
Hope this helps ,but as i said unless you are using the scanner day in day out with the same pic on the same medium,then it is a matter of trial and error
oh and make sure you either phsically or electronically mask any extraneous parts of the image --:)
Regards
Rich

Hi, Gulp!

Welcome to the thread. Thanks for the information. I didn't know about putting a transparency between the pic and the scanner. I'll have to give that a try next time.

Thanks Swampy for the welcome, and let me know how you get on with the transparency -ive seen it work quite a few times without much image degradation. After reading a post earlier i dont think i'll be offering any D&B advice -LOL

>>>>>After reading a post earlier i dont think i'll be offering any D&B advice -LOL

I get your drift. <wink>

There is no magic formula for removing a moire. Gently nudging the image around on the scanner to minimize the interference between the scanner's ccd pattern and the halftone dots can help. After that it's just a matter of blurring out the halftone pattern and painting detail back into the image. The one other thing you could try is scanning the images at very high resolution and then not re-screening them at the printing stage (i.e. using the already existing halftone). This might require that the printer do the scanning, however. You'd have to work closely with the printer to achieve good results that way, but it is a method that is used in magazine printing to pick-up old ads for which there is no existing film. Good luck.