Message-Id: <mailto:199505042146.QAA24069@library.wustl.edu> Date: Thu, 4 May 1995 16:44:41 CST From: David Riecks <mailto:riecks@CC-MAIL.AGCOMED.UIUC.EDU> Subject: Re[2]: SCANNING RESOLUTION To: Multiple recipients of list IMAGELIB
If you are planning on using your own desktop scanner, you might consider scanning at the highest rate, and using compression such as JPEG to save on the file size space. The bigger the file you can start will the better your results will be. I've never gone out to microfilm but a good rule of thumb for best results is to capture at least 1.25 times the size of the pixel per inch (ppi) of the output device.In other words when we are planning to use a digital image in a color publication, we start with a file the same dimension, but 1.25 times (or more) the ppi rate. Actual example for a 5" x 7" color image that will be output on a 155 line screen we use a file that was scanned at 200 or 225 ppi.
Just my $.02 worth.
David
********************************************************************** *| David Riecks | "There's a fine line between |* *| University of Illinois | fishing and just standing on |* *| mailto:riecks@uiuc.edu | the shore like an idiot." |* *| mailto:71543.1617@compuserve.com | Steven Wright |* **********************************************************************
>We have started a project here at Brandeis scanning papers from the Andrei
>Sakharov Archives. The materials in the archives consist of typescript,
>manuscripts, and some photos. We are scanning at 400 dpi resolution in
>grayscale primarily, with some materials in color. We are using 400 dpi
>resolution with the intent that microfilm can be produced from the
>digitized images in the future.
>We are interested in hearing from others whether 400 dpi 8-bit grayscale
>and color images are considered sufficient for this purpose, or whether we
>should increase our scan resolution to say 600 dpi grayscale and true color
>for preservation-quality microfilm. Any recommendation will be appreciated.
>
>Tanya Brun
>Archive Assistant
>The Andrei Sakharov Archives
>Goldfarb Library
>Brandeis University
Thanks, Alan
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