Message-Id: <199611270017.SAA03800@library.wustl.edu> Date: Tue, 26 Nov 1996 16:11:30 PST From: Ricky Erway <mailto:BL.RLE@RLG.ORG> Subject: Re: Minolta scanner and grayscale To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU
REPLY TO 11/26/96 14:22 FROM mailto:IMAGELIB@LISTSERV.ARIZONA.EDU "IMAGELIB": Re: oversize scannerMinolta watchers,
Lou Sharpe is the expert I turn to in this arena. He has been working with Minolta to address this issue on behalf of all of us who enthusiastically endorse Minolta's non-damaging, scan-from-above approach for bound volumes, yet still ask for more!
Last I heard, Lou had managed to get agreements and equipment from Minolta to carry out the necessary work. It took testimonials from several of us in the field to convince Minolta that it is worth their while to take this step. We CAN make a difference...
Ricky Erway Research Libraries Group
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<excerpts from a message from Lou on this topic; his address is at the end of this message>
The flavor of the device which attaches directly to the Minolta digital copier allegedly does output grayscale, with the halftoning/dithering performed in the attached copier which uses the grayscale for that purpose.
My company, Picture Elements, is developing ... a grayscale scanner interface and processing PCI-bus board. We are ... undertaking the integration work to make the Minolta and our board work together to capture [AND OUTPUT] grayscale. ... this integration work will then be available as a standard product to the library community.
Our board can save the raw 400 dpi, 8 bit grayscale while simultaneously performing a variety of other real-time hardware operations (as needed) including grayscale deskew, grayscale scaling to any value (including up to 600 dpi), contrast brightening, JPEG compression, and our high-quality edge thresholding and despeckling to create a binary image.
A typical scenario might have a 600 dpi binary image created of all-text pages along with a 100 dpi high-compression JPEG for Web access, with a second, 400 dpi JPEG kept at a low compression ratio to serve as what we call a "surrogate original" -- a preservation-quality image capable of later being reprocessed if quality assurance (for which we have some automated methods) finds the binary image lacking in any way. This way no re-scanning is necessary.
For pages containing illustrations or other tonal content (marginalia, other low-contrast features), a 300 dpi JPEG might be the primary preservation-quality image. In an environment where national treasures or exceptionally endangered items are involved, the raw grayscale could also be saved.
Louis H. Sharpe II mailto:lsharpe@picturel.com Picture Elements, Inc. 303-444-6767 410 22nd Street, Boulder, CO 80302 USA fax 303-415-1392 http://www.picturel.com ftp://ftp.picturel.com/pub/incoming
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