Message-Id: <199805132031.NAA53336@dns.ccit.arizona.edu> Date: Wed, 13 May 1998 16:18:22 -0400 From: Terry Kuny <mailto:Terry.Kuny@XIST.COM> Subject: Re: Request for info on images to microfilm To: mailto:IMAGELIB@LISTSERV.ARIZONA.EDU
Hi,Some caution is probably warranted in digitization first and then microfilm. Careful tests with respect to quality of materials should be undertaken. Resource considerations are probably also key, especially vis-a-vis the technical services and infrastructure that you have available to you.
There are two reports that you might want to note here:
1. The Project Open Book Report from Yale University on conversion of microfilm to digital imagery.
Paul Conway, Conversion of Microfilm to Digital Imagery: A Demonstration Project. Performance Report on the Production Conversion Phase of Project Open Book, Yale University Library, August 1996. I *think* this is available from the Commission on Preservation and Access but I don't recall seeing an electronic copy of this.
See also, Paul Conway, "Yale University Library’s Project Open Book: Preliminary Research Findings," D-Lib Magazine, February 1996 (http://www.dlib.org/dlib/february96/yale/02conway.html) This is by Paul Conway and is available from the Commission on Preservation and Access. Preliminary findings were documented in DLib Magazine:
http://www.dlib.org/dlib/february96/yale/02conway.html
2. The work done at Cornell on Digital to Microfilm. There is a report at:
http://www.library.cornell.edu/preservation/pub.htm
SUMMARY FINDINGS OF THE CORNELL PROJECT
The following findings and recommendations have been reached as a result of the project:
QUALITY
1.Computer Output Microfilm (COM) created from 600 dpi 1-bit images scanned from brittle books can meet or exceed ANSI/AIIM microfilm standards for image quality and permanence. 2.No detectable loss of resolution was observed in recording the digital images onto COM. 3.The quality of digital images created at the same resolution and bit depth will be superior when brittle books are scanned directly from paper rather than from microfilm copies. 4.COM can be scanned to re-produce high quality digital images in the event that the original digital files become unreadable.
Recommendation:
Standards for COM production and inspection must be developed and adhered to by institutions and service bureaus alike. The Technical Advisory Committee to the project recommends that quality standards for digital imaging of paper source documents be developed and that modifications be made to the standard microfilm quality control practices for evaluating density, resolution, reduction ratios, targets, film size, and bibliographic completeness of COM.
COST
1.In a hybrid program to create both microfilm and digital images, the costs associated with the scan first approach appear to be less than those incurred in the film first approach. If extant film is scanned, as was the case in Project Open Book, then the costs favor the film first approach. If only digital images are to be produced, the costs of scanning from paper versus film are comparable. However, the cost figures produced by both Cornell and Yale reflect the nature of demonstration projects rather than ull production processes.
2.Creating in-house scanning services may not be as cost-effective as outsourcing the work, provided clear guidelines are developed to ensure compliance with quality (and pricing) requirements suitable to library and archival applications.
Recommendation: The findings from the Cornell COM project represent a financial benchmark against which to measure costs associated with developing and maintaining a digital archiving program.
PROCESS
1.The film first and scan first approaches are both viable solutions in a hybrid program. The decision to go with one approach over the other will depend on a range of variables associated with the attributes of the originals, institutional capabilities, and the availability of appropriate imaging products and services.
2.The Cornell/Yale projects evaluated the use of high resolution bitonal scanning to produce digital versions of brittle books. Further investigation into the quality, processes, and costs associated with grayscale and color scanning should be conducted. 3.Cornell adopted a "reasonableness" standard for determining the copyright status of twentieth century brittle books to be included in a hybrid approach.
Recommendation: Cornell and Yale recommend that the National Endowment for the Humanities support a high level conference to assess the findings of their projects; to make recommendations for best practices on the creation and use of conventional microfilm and COM in a hybrid approach; to consult with vendors of imaging services and products in adopting these practices; to identify areas needing additional research and development; and to evaluate the role of the hybrid approach in broader digital preservation efforts.
I hope this helps.
Regards,
-terry