Message-Id: <mailto:199503201424.IAA15067@library.wustl.edu> Date: Mon, 20 Mar 1995 09:18:38 EDT From: Lee Dirks <mailto:Lee_Dirks@OCLC.ORG> Subject: Re: Microfilm Digitization To: Multiple recipients of list IMAGELIB
Message: > I'm curious why you don't just SCAN the source material using a 8
> bit scanner giving you 256 gray level steps, and then make raster
> com for the archive?
Because COM does not meet even the basic standards for preservation quality microfilm, specifically the RLG Guidelines for preservation microfilm. Our greatest concern is the longevity of the master negative, when -- if properly processed and stored -- should last at least 500 years. COM does not have that lifespan or quality. Nor do digital scans of the same images. As Rothenberg states in his January 1995 Scientific American article, "It is only slightly facetious to say that digital information lasts forever--or five years, whichever comes first." -Lee Dirks (Preservation Resources, Bethlehem, PA (800) 773-7222)