Re: research, index, db...

Tim O'Connor


Many all-in-one scanner/printer/copiers have descreen filters
in their TWAIN drivers. But your library copier probably does
not do this. Too bad because descreen is required to pull a
clear image of a photograph from a halftone print (like from
a book or magazine).

The "photo mode" tells the copier that it's NOT a halftone!

Tim O'Connor

At 10/18/2010 09:53 PM Monday, you wrote:
I have found that some university libraries take the output from the
copying machine directly to a PDF or other file type that can be
captured on a memory stick, or if you are a student you just email it to
yourself to eliminate paper copies. I find this a very handy feature so
I do not accumulate a large stack of photocopies to take home and file.
Unfortunately I couldn't find a "descreen filter" in the copy machine
options when copying photos in railroad journals. Do some machines copy
machine have this option? The "photo mode" didn't "descreen" the image.

Bob Witt

Charlie Vlk wrote:

Tim brings an important bit of information up in his note..... I was
not aware that the scanners had a "descreen filter" which (I looked it
up on Google) eliminates problems you may get from scanning printed
materials that have halftone dots. Since many of us do scan reference
materials this information may prove to be useful.

I concur. Digital bits take up very little space! Just use the
"descreen filter" on your scanner and put something dark behind
the page to limit bleed-through. And you can sell the magazines
at a flea market instead of throwing them out.

Tim O'Connor

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