Cornell/Xerox/CPA Joint Study in Digital Preservation — Progress Report Number 2
| DOI | https://doi.org/10.1108/eb045147 |
| Pages | 155-163 |
| Published date | 01 March 1992 |
| Date | 01 March 1992 |
| Subject Matter | Information & knowledge management,Library & information science |
Technical Report
Cornell/Xerox/CPA Joint
Study in Digital
Preservation —
Progress Report Number 2*
Introduction
Cornell University and Xerox Corporation, with the support
of the Commission on Preservation and Access, have been
collaborating in a project to test a prototype system for recor-
ding brittle books as digital images and producing, on de-
mand, high quality and archivally sound paper replacements.
The project
goes
beyond
that,
however, to investigate some of
the issues surrounding scanning, storing, retrieving and pro-
viding access to digital images in a network environment.
Considerable progress has been made in the course of the
past ten months. While full findings will only be available at
the end of this project, the following tentative conclusions
about the use of digital technology have been reached.
— 600 dpi scanning and printing results in a high
quality paper replacement for brittle textual
materials. It also currently represents the highest
level of resolution achievable in a production
environment for black and white materials.
— Creating microfilm that meets preservation
standards from digital files is feasible today.
— Digital technology represents an affordable
alternative to microfilm for reformatting brittle
material. It can serve as a means for capturing
material and producing microfilm while allowing
for the flexibility in storage, distribution and
access — and the potentially greater quality —
associated with the technology.
— Digital technology has the potential to
revolutionize access to material and to change the
library's role in making resources available
radically. Prerequisites to these changes include
* This article is reprinted with the permission of The Com-
mission on Preservation and Access, 1400 16th Street NW,
Washington DC 20009, USA. Excerpts of this report pre-
viously appeared in the November-December 1991 issue of
the Commission on Preservation and Access Newsletter. The
report was also selected for publication in the
1992
Advances
in Preservation and Access, vol. I (Meckler).
making digital files available in a network
environment and providing mechanisms for
accessing those files easily and quickly.
—
A
meaningful evaluation of digital technology's
impact requires the development of
a
carefully
chosen and expanding digital library of
thematically-related documents. For this reason,
digital technology could have broad implications
for the selection of material to be preserved.
This second status report focuses on activities that support
these tentative findings. It primarily discusses progress in the
areas
of
quality,
microfilm, productivity and cost
estimates,
net-
working, system architecture, local access, and selection. The
final report of this project, which has been extended through
December
1991,
will include detailed analysis to support these
positions and recommendations for future directions.
Quality
Six hundred dpi scanning and printing results in a high
quality paper replacement for
brittle
textual
materials.
It also
currently represents the highest level of
resolution
achievable
in
a
production environment for black and white materials.
Like microfilm and photocopy, a high resolution digital
image can faithfully reproduce an image of a page, which is
critical when replacing rapidly self-destructing books. Be-
cause a digital image is an encoded representation, there are
certain advantages to copying a page digitally. First, the
image can be reproduced over and over again with no result-
ing loss of quality. Second,
a
digital image can
be
manipulated
in a number of ways to improve image capture. It can be
edited and density levels adjusted to remove underlining or
stains.
A page may be cropped so that edge detection, com-
mon in photocopying, is eliminated. On-screen inspection
can take place at the time of initial set-up, and adjustments can
be made prior to scanning.
This ability has substantially reduced the number of rescans
required in quality control. Xerox Corporation is currently de-
veloping
a means
for automatically segmenting
a page
contain-
ing halftone illustrations so that the images may be captured as
gray scale and the text as high contrast black and white. This
system upgrade is expected to be in full operation by mid-
autumn
1991.
An analysis of
the
quality of illustrations scanned
using this process will be included in the
final
project report.
A
primary goal of
the
Cornell/Xerox/CPA Joint Study is to
evaluate the paper output printed on the Xerox Docutech, a
recently-released Xerox product that prints 600 dpi pages
from scanned images at the speed of 135 pages per minute.
Paper copies are being produced for each of the 1000 books
included in the project. The quality of the paper copy is ex-
The Electronic Library, Vol. 10, No. 3, June 1992 155
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