A client has asked me to clean-up a hi res scan (13.5mb, grayscale, tiff) of a photographic copy of an old photograph engraving. The linescreen on the original is very coarse. This will be enlarged several hundred percent for digital reproduction in a display. The dot pattern in the original cut is very visible when enlarged. They would like the dot pattern minimized or better yet, removed, without making the image look retouched.
Client has heard of "interpolation" software to minimize the dot pattern and I am in the dark.
If there is no way to clean this up decently with software (the scan was done by the local historical society) are there any suggestions to accomplish this. I am competent doing retouching, but this image has several several humans and I need to provide a professional job.
Patience and time, little by little, inch by inch. Plan to spend some time on this. Work for a while and then do something else. Since you know about retouching, I believe that if you take enough time and work at this systematically you can do it.
If you want to post a link we might be better able to pitch in and offer help.
While keeping the dots would provide a nice effect blown way up, unless the image is descreened, he’s gonna have a hell of a time retouching it, what with cloning dots around and trying to keep them lined up.
The best way to descreen is during the scanning process, using a scanner that has descreening as an option.
Using gaussian blur after the fact of scanning, generally does not produce very good results.
Client has heard of "interpolation" software to minimize the dot pattern and I am in the dark.
Sounds like a guy with a little bit of knowledge tossing buzz words about. Dangerous.
What kind of display is this? What is the actual print resolution for this project? for something that will be printed extremely large a good way to get the size and not have to deal with the moire pattern going crazy on you is to just decrease the print resolution from 300 or whatever to 120 that will boost your print size considerably and keep the image basically the same. There are descreening software out there, some kinds you can get with your scanner. I have one in my scanning software that cuts down on the patterns considerably!
How big will the final print be? A 13.5MB scan will only take you to about 16" x 20".
I would get it rescanned.
Get whoever makes the new scan to put the original photograph on the scanner at an angle of 15°. While they are about it, get them to make two scans: one using the De-screen filter and one without it.
I agree with Ann that you should probably start with a higher resolution scan. Any attempt to descreen electronically is going to soften the image somewhat, and there will be little you can do to then sharpen it up without creating other problems. And the more retouching you do (and the larger the retouched print), the more phony the image will look.
Another problem is how coarse the original screen is and how large the original image is. If the image is from a relatively coarse newspaper halftone, the results will be less satisfactory than if it were from, say, a fine art book.
Buko’s idea of leaving the does in there does have merit — depending upon the image, and how much detail it has, it may actually wind up being the most attractive version of this scan.
I too like keeping the dots for realism if you cannot get a better scan. It should be able to be done with careful use of the Clone Stamp tool. Trouble is clients so often don’t like what we like. You may want to make two versions, one fully without dots by painting/cloning/erasing them out on new layers (basically, new art). Sounds bad to me, but I am no longer surprised by clients’ perferences…
