Feature Articles
Joint RLG and NPO Conference on Guidelines for Digital
Imaging
Nancy Elkington
Program Officer, Research Libraries Group
bl.nee@rlg.org
and
Neil Beagrie
Collections and Standards Officer, Arts and Humanities Data Service
Executive
neil.beagrie@ahds.ac.uk
Over ninety people from North America, Europe, and Australia convened at the University of Warwick (UK) September 28-30, 1998 for a first-of-its-kind working conference. The Research Libraries Group and the National Preservation Office (NPO) of the UK and Ireland joined forces to focus on creating an international consensus in the development of guidelines for digital imaging and digital preservation. Proceedings for the conference will be made available at the conference Web site (UK and Europe link) and in print form (from NPO) in the coming months. Updates that include summaries of plenary discussions, small group recommendations, and follow-up actions by RLG and the NPO will appear on the Web site in the coming weeks. Meanwhile, this abbreviated version is being made available as soon as possible after the event. Many thanks are due to speakers and delegates for making this a memorable and inestimably useful conference.
Fifteen speakers from the US, the UK, Canada, and Australia shared insights and challenges on selection issues, physical and editorial preparation requirements, image capture techniques and rationales, metadata approaches, and digital preservation imperatives. Delegates from over a dozen countries were able to air their opinions in small group discussion sessions and open question/answer periods amid several plenary sessions. And all participants took great advantage of the unique opportunity to exchange ideas and trade experiences less formally in hallways, lounges, and dining rooms over the three-day conference.
Anne R. Kenney (Cornell University), the conference keynote speaker, is one of the world's most experienced professionals currently engaged in exploring digital technology and seeking best methods for applying it to the needs of libraries and archives. In her remarks she acted as teacher and mentor, sharing the breadth of her experience in a series of ten guiding principles. Two of the most critical of these, at least in the context of the conference, were: "Don't reinvent the wheel" and "Don't reinvent an old wheel." Participants were admonished to avoid drawing too literal an analogy between preservation microfilming strategies and work flows and those that are relevant to digital conversion efforts. She further argued against the development of guidelines that are too rigid or too narrowly conceived; instead, she suggested that experts should be working toward agreements on providing guidance rather than guidelines. Kenney encouraged the group to undertake that which is doable, and to acknowledge the gap between the ideal and the possible. She also emphasized the relationships and inter-dependence of decisions taken during the selection, preparation, and capture in digitization projects and the importance of a coordinated approach, citing the recent AHDS study and its advice on developing a strategic policy framework for creating and preserving digital collections. Finally, and most persuasively, she urged participants to recognize that sometimes "reasonable, well-informed people can disagree" on what constitutes best practice.
Selection
Guidelines for Selection, the first of three focused sections
combining formal presentations and small group discussions, was
moderated by Julia Walworth (University of London Library); the
podium was shared by speakers Janet Gertz (Columbia University) and
Paul Ayris (University College, London).
Speakers identified examples of selection guidelines available on the Web, and summarized some of the common criteria used in digitization projects, such as whether the original item is damaged or in danger, its in high demand, or has significant intellectual or artifactual value. It was stressed that most digitization is access driven rather than preservation driven at present. Discussion raised the issue of whether preservation of digitized images would prove more costly than re-digitization at some future date. It was generally concluded that this assumption may often be curtailed by the need to conserve the original objects and to invest in converting materials not yet in digital form.
The need for guidance rather guidelines proposed by Anne Kenney was widely endorsed. At the same time it was recognized that some education is needed to achieve and implement this: often in questions on digitization a single solution or standard is sought. The answer to such questions invariably begins with "it all depends..." There is a learning curve on how to choose appropriate solutions and standards which are "fit for purpose," and that meet project and institutional needs and requirements.
Recommendations coming back to the audience from the small group discussion included:
Preparation
Preparation, the second of three in-depth sessions, was chaired
by Alison Horsburgh (National Archives of Scotland). Joining her to
address issues of physical preparation was John McIntyre (National
Library of Scotland); Ann Swartzell (Harvard University) addressed
issues characterized as editorial preparation.
Papers presented were wide-ranging and detailed, drawing on the extensive experience of the speakers. Issues addressed included protecting the original item; assessments of condition and identifying vulnerable material; preservation/conservation records; procedures for safe handling; identifying suitable scanning methods; disbinding (when, if, and how!); scanning methods and their implications for both the originals and the quality of the digital image; use of intermediates and surrogates; types of lighting and their effects; and institutional policies for post-scanning access to the original items. The lessons learnt from preservation microfilming projects for preparation of materials and planning production workflow were also discussed, together with changes needed for digital production regimes. The importance of cataloging and bibliographic control were also emphasized. The experience of a number of projects underscored the fact that preparation, cataloging, and provision of metadata may be twice or three times the costs associated with image capture.
Recommendations coming back to the audience from the small group discussion included:
Image Capture
Robin Dale (RLG) led the session on image capture, arguably the
most complex of the three topics given extensive attention in the
conference. Stephen Chapman (Harvard University) and Jane Williams
(Technical Advisory Service on Images) explored a range of technical,
intellectual, and educational issues. All the speakers emphasized the
inter-relationships and decisions taken between image capture and the
preceding stages of selection and preparation.
Stephen Chapman outlined the different trade-offs between image quality, cost, potential or acceptable damage to the original, use of intermediates, and the method of scanning employed. He also highlighted the paradox that while many digitization projects are undertaken to reduce use of originals, the actual handling of the originals during the process of digitization may be collectively higher than at any other period in the history of a collection. The conservation implications of digitization itself need to be considered and the impact of digitization on originals minimized. Digital cameras were discussed with the different requirements of and implications for getting a good signal, getting a good scan, and getting a good image. The importance of calibrating the overall system and components used for digitization was emphasized together with the view that, in addition to guidance, there may be a need to identify at least minimum requirements for preservation quality imaging. Different aims and "capture levels" for image outputs were also discussed: the four image levels used by Corbis of rendered, faithful to photographer's intent, original photograph rendered (restored), and original film rendered (film bias corrected) were summarized.
Jane Williams outlined the work of the Technical Advisory Service for Images (TASI), a national service for the UK higher education community. Her experience again underlined the need for education rather than prescription, and for ensuring that digitizers understand the consequences of different choices they will face so that they can then make informed decisions. A wide-ranging overview with recommendations was presented of image capture, imaging methodologies, formats, acquisition, archiving, quality control, file naming, and delivery and presentation to users. The many clear recommendations included the suggestion that digitization projects should consider an initial "dummy" run at the beginning of a project to allow for experimentation, calibration of systems, developing capture procedures and quality checks to reflect the fact that quality increases as scanning procedures are refined and experience developed.
Recommendations coming back to the audience from the small group discussion included:
Preservation Metadata and Digital Archiving
Two conference sessions were linked and intended to give
participants an overview of the issues and challenges inherent in
addressing metadata and digital preservation needs. Michael Day (UK
Office for Library Networking) and Margaret Hedstrom (University of
Michigan School of Information) gave excellent presentations on
metadata and digital archiving, respectively.
Michael Day surveyed the array of metadata types and models put forward by a host of organizations with distinctly different purposes. He pointed participants to the work of three projects/organizations that are specifically addressing metadata requirements in the context of files that are intended to survive over the long term: RLG's Working Group on Issues of Preservation Metadata, the Making of America 2 (MOA2) White Paper, Version 2.0: Metadata Section, and the Consortium of University Research Libraries' CEDARS Project. Day concluded that there is a need for integration of preservation metadata models with other metadata forms, and assured the group that the CEDARS Project will, as one of its outcomes, develop guidance documents for others interested in metadata supporting digital preservation.
Margaret Hedstrom addressed digital preservation by encompassing the larger world of digital documents, whether they are "born" digital or arrive in that form after an analog-to-digital conversion effort. Underscoring the disjuncture between implementations and best practices, she suggested that best practices will always be influenced heavily by the nature of the source documents, known and anticipated uses of the material, and by the institution's technical capacity. Hedstrom argued for the reliance on non-proprietary file formats and encoding schemes, cautioning that conversion into such formats must be balanced against a series of risk assessments (information loss, source integrity, cost of conversion). Further, she set out best thinking in storage and maintenance techniques, identified areas where we are currently lacking guidance and experience, and listed a range of techniques used to ensure access to digital materials into the future. She concluded by reporting on a survey of RLG members as to their digital preservation needs; a final report will be made available in the RLG Web site late in 1998. One outcome of the survey already identified in discussion with the audience was the absence of adequate institutional collection policies for electronic materials and the need to support and guide their development.
Conclusions
An international reaction panel was formed in order both to
reflect activities outside of the US and UK contexts and also to
point conference organizers toward new ways of thinking about how to
address the dozens of needs expressed over the course of the three
days. Karen Turko (University of Toronto), Seamus Ross (University of
Glasgow), and Colin Webb (National Library of Australia) shared the
spotlight during this session.
The reaction panel provided an overview of current digitization initiatives in Canada, the UK, and Australia. Karen Turko provided an overview of the Early Canadiana Online Project, University of Toronto Library Digital Initiatives, and the Canadian Initiative for Digital Libraries. Seamus Ross stressed the need for strategic vision to develop digital resources and their preservation, and referred to national initiatives within Higher Education in the UK such as the Arts and Humanities Data Service (AHDS) and CURL Exemplars in Digital Archives (CEDARS). Drawing on his experience as Information Technology (IT) Adviser to the UK's Heritage Lottery Fund, he stressed the very different needs of funding agencies. Funders need to know risk assessment, how to identify best practice, and how to assess the public benefit of digitization projects. The staff of digitization projects must understand and be able to apply guidance and identify the best trade-off of different requirements and standards for their projects. Colin Webb spoke of the IT initiatives in Australia, particularly at the National Library and the National Archives, and their relationship with local and regional institutions. He stressed the need to focus on the initial development of infrastructure and appropriate tools such as the customized harvesting tools for Web pages developed for the PANDORA Project. The importance of a sense of local ownership of policies and guidance was also emphasized - the benefits of learning from others and not re-inventing the wheel need to be tempered with "checking the wheels" ("kicking the tires") and ensuring commitment from the participants.
Peter Fox (Cambridge University Library) summarized the conference by harking back to Anne Kenney's keynote message that this is an unprecedented opportunity for action. He asserted that there were two main themes that we need to pay attention to: first, that there are several areas in which consensus and agreement is already possible, and second, that we need to think strategically of how best to persuade institutions to adopt guidelines and guidance provided. Fox encouraged RLG and NPO to work closely with others where needed expertise lies outside of their purview, to "harness expertise wherever it can be found." Finally, he urged all those in attendance: "Don't lose the momentum."
The Role of National Initiatives in Digital Preservation
Margaret Hedstrom
Associate Professor of Information, University of Michigan
hedstrom@umich.edu
The digital world is often characterized as chaotic, and the terrain of digital preservation is no exception. In recent years the research community has witnessed a flurry of activity around digital archiving and digitization for preservation and improved access to materials in traditional formats. What is less clear is whether the time, energy, and money invested in digital preservation initiatives will produce strategies that can be generalized and, at the same time, are flexible and robust enough to satisfy the specific local and institutional needs. This article uses digital preservation initiatives in the United Kingdom, Sweden, and Australia to illustrate different models for national leadership and coordination.
Digital preservation is a global problem in a world where global communications transcend national boundaries and where hardware and software are sold on an international market. Numerous reports emphasize the development and adoption of international standards as an underpinning of long-term digital preservation strategies. Sharing research, training, and best practices is also a good way to avoid reinventing the wheel and to spread the costs of research and development. Some may wonder whether national strategies are needed in this type of environment and, if so, what useful role they might play. The following three examples illustrate areas where coordination and resource sharing on a national level can mediate between the particulars of local situations and global initiatives without creating isolated islands of uncoordinated activities.
Digital Programs in the UK
Digital preservation activities in the UK are far too extensive even
to list in a short article such as this.
The National Preservation Office at the
British Library is developing a national strategy for digital
preservation that includes assembling best practices; developing
scaleable and costed models for converting, accessing, and preserving
digital information; identifying areas needing research and
evaluation; coordinating UK initiatives in these areas; exploring
funding models; and mobilizing resources. In the UK, sectoral
coordination within higher education and in disciplinary areas will
support development of a national strategy.
The CEDARS Project is a higher education initiative funded through the eLib Programme of the Joint Information Systems Committee (JISC). CEDARS stands for "CURL (Consortium of University Research Libraries) Exemplars in Digital Archiving." The project is sponsoring practical demonstration projects and strategic working groups on Access Issues, Content Issues, Digital Preservation, and Infrastructure and Integration. The project's Access Issues Working Group has produced a useful summary of models for preservation metadata.
In July 1998, the Arts and Humanities Data Service (see Highlighted Web Site) released "Strategic Policy Framework for Creating and Preserving Digital Collections." The report, prepared by Neil Beagrie and Daniel Greenstein, includes recommendations on digital preservation, standards, policy, and future research based on case studies of real life concerns of data bank managers, digitizers, funding agencies, institutional archives, academic data archives, and legal deposit libraries. This project, also funded by the JISC eLib Programme, is part of a series of studies guided by the Digital Archiving Working Group, composed of members from UK Higher Education Libraries, Data Centres and Services, the British Library, the National Preservation Office, the Research Libraries Group, and the Publishers' Association.
Sectoral Leadership and Coordination in Sweden
Sweden, which does not have a national preservation office or a
national preservation strategy, relies heavily on national
institutions in the library, archives, and museum sectors for policy
and guidance. The Royal Library is
especially active in metadata standards and digital preservation
strategies for electronic publications. The Royal Library is
sponsoring a project to implement legal deposit legislation for
Swedish electronic publications and Web pages. Under the rubric of
"Kurturarw3",
the Swedish Web Archiving Project is using robots to identify and
download all Swedish Web pages. The project has the potential to
develop methods that are scaleable, because they use software agents
to identify, download, and classify Web pages while working within
the focused domain of Swedish Web sites. In August 1998, the National
Libraries of the Netherlands and Australia joined with the Swedish
Royal Library to form a project called
"PreWeb" to
sponsor discussions and information sharing about preserving World
Wide Web documents. The Swedish National
Archives coordinates activites in the archival sector where there
is an extensive project underway at SVAR, a technical and advisory
unit of the National Archives, to digitize church registries and
other genealogical information. There is less coordination among
museums, although
INSAM,
headquartered at the Nordic Museum, is providing leadership in the
development of common standards, policies, and training for museum
databases and other technology applications.
Digital preservation issues are serving as a catalyst for joint activities and coordination among the archives, library, and museum communities in Sweden. In May and June 1998, this author taught a five-day digital preservation course in three different Swedish cities, organized by the ABM (Archives, Bibliotek, Museum) group. The workshop created opportunities for professionals from each of these sectors to meet and discuss digital preservation problems and to consider shared solutions across institutions that traditionally have been identified with the types of materials they collect. Nearly 100 archivists, librarians, and museum curators participated in the Spring training program, and many resolved to use the training as a basis for future collaboration.
Distributed Responsibilities in Australia
Many professionals are looking to Australia for creative ideas and
bold strategies for digital preservation and access. The Australians
have attracted considerable attention in the archival community with
their policy on electronic records management as a shared
responsibility and the release of the first records management
standard (AS 4390) in December
1996. Australian electronic records management strategies assume that
digital archives will be distributed and that the creators of digital
materials and the archives must work together to develop
technologically feasible and cost effective means to preserve
corporate memory in the digital age.
The National Library's PANDORA Project is capturing, archiving, and providing long-term access to significant Australian on-line publications. The Selection Committee on On-line Australian Publications (SCOAP) has developed a set of selection guidelines. PANDORA currently provides access to more than 1,000 Australian electronic journals, magazines, and ephemeral digital items. Like the policies being adopted for preservation of official electronic records, the Australian national strategy for long-term access to electronic publications assumes cooperative arrangements among creators, publishers, libraries, and archives. To facilitate coordination and reinforce the linkages between preservation and access, the National Library recently merged the former National Preservation Office, the Distributed National Collections Office, and its International Relations Office, and formed National Initiatives and Coordination. Like similar initiatives elsewhere, the strategies include development of standards, use of metadata, establishing criteria and priorities, and distributing responsibility for preservation.
Conclusion
Returning to the original question of whether there is a role for
national preservation strategies in a global digital environment,
these three examples demonstrate that national policies and
strategies remain useful, but that each national strategy may well
adopt quite different approaches for infrastructure development,
coordination, and funding. Dividing responsibility for preservation
and developing guidelines and criteria for selection are areas where
coordination on a national level seems particularly pertinent.
Australia, Sweden, and the UK all have legal deposit legislation, but
each country approaches legal deposit of electronic publications
differently. The Swedish strategy is designed to acquire digital
copies of all Swedish electronic publications, including Web pages.
The current emphasis is on capture because of legal questions about
access and a sense of urgency about acquiring copies of electronic
publications before they vanish. The Australians are pursuing a
strategy based on distributing responsibility between the National
Library for electronic publications of national significance and
state and local authorities for significant publications in their
regions. Both of these approaches have merit, but what is more
significant is that they begin to demarcate areas of responsibility
for preservation that allow other institutions to turn their
attention to neglected issues. Variation in national legislation
governing copyright, legal deposit, access, and privacy also requires
specific national strategies that conform to current law and legal
traditions.
Leadership from national institutions, advocacy organizations, and funding bodies can direct efforts toward solving classes of problems, as many of the JISC-funded eLib projects illustrate. Coordination is also an essential element in an environment where digital materials are distributed and responsibility is shared. These examples illustrate how coordination between sectors, such as the linkages between higher education and discipline-based data centers in the UK, or among libraries, archives, and museums in Sweden, might be accomplished on a national scale. Efforts to achieve this degree of coordination on an international level often become too unwieldy or too distant from many of the actors and stakeholders. There is plenty of research and development to be done on an international scale in the areas of standards, software and systems development, and interoperability, but these efforts should not negate the contributions that national initiatives and strategies can make to a global infrastructure for digital preservation. In spite of the variations from country to country, there is also ample opportunity for sharing lessons and deriving general principles for national preservation strategies. At the moment, there is some cross-fertilization between projects, but there is a ways to go before the preservation community has models for national strategies that can be modified readily to meet local conditions.
Technical Feature
Light Levels Used in Modern Flatbed Scanners
Timothy Vitale
Paper and Photograph Conservator and Consultant, Preservation
Associates
tjvitale@ix.netcom.com
Introduction
It has been said in some quarters that scanning is equivalent to
exposing an object to a day's, or a year's worth of sunlight. This
article examines that claim, and will show that not only is this not
true, it may well be impossible.
Scanning an image on a flatbed scanner involves passing a sensing array (Charged Couple Device, CCD) along an object resting face down on a glass platen. The array has a light source attached. Today these sources are usually of the cold-cathode type (1) because of their color characteristics and cooler operating temperature. The method is similar to that of a photocopy machine. This has caused a misinterpretation of the scanning process. Until recently, copy machines used very strong light to produce an image on a relatively light-insensitive coated drum, which resulted in toner being deposited onto paper. The amount of light needed was dictated by the low sensitivity of the coating on the copy transfer drum. Today's CCDs have sensitivities between 0.1 and 0.001 lux. (2) This means that a CCD does not need blazingly bright light to achieve its goal. Scanner lamps have evolved for a technology with greater light sensitivity.
Measuring Light Levels
A year's worth of sunlight delivered in 1-2 minutes would vaporize
most paper-based materials. A day's worth of sunlight would do
serious damage. A year's worth of sunlight on the west coast of the
United States is about 230 Mlx-hrs, or million
lux-hours.(3) A day would be 0.63 Mlx-hrs.
Based on that exposure, seven average days of full, outdoor,
horizontal sunlight exposure would permanently damage an average
artwork on paper (see below). The highest possible light exposure on
the planet is 290 Mlx-hrs with 60,000+ Lux on a horizontal
surface.(4)
A day of standard museum light exposure would range from 600 to 1200 lx-hrs (50-100 lux for 12 hours of exposure) or 0.000600 - 0.001200 Mlx-hrs. Daylight is usually excluded for the display of works on paper. Using the standard "conservation" protocol for the display of paper-based materials, an artifact is expected to have a life of approximately 4.3 Mlx-hrs.(5)
In 1992, K.M. Colby suggested a new museum display policy that was
based on fading rates developed from the ISO blue wool
standards.(6) She defined various categories
for museum objects based on light fading to a very low 0.01 density
change (
d).
(7)
Category 1 includes sensitive artworks whose members show just
perceptible damage, 0.01 d, at an
average of 1.2 Mlx-hrs (range: 0.4-3.6 Mlx-hrs). This category
would include early albumen prints, most color photographs, Polaroid
images, some watercolors, pastel or ink drawings, works on
newsprint, and a range of other non-paper artworks.
Category 2 artworks are expected to sustain an average of 32 Mlx-hrs (range 10-100 Mlx-hrs) of exposure before showing just perceptible change due to non-UV light exposure. Category 2 contains low stability paper-based materials, B&W gelatin prints, and most color slides. I would also include black printers-ink engravings/etchings on average paper and documents printed earlier than the 1850s with carbon ink on average paper.
Category 3 materials, which include stable media on the highest quality paper, toned B&W photographs, and carbon inks, can undergo 300 Mlx-hrs of light before perceptible change.
Table 1 offers summary data on light intensity measurements for direct sunlight, exhibition conditions, and flatbed scanning, and compares those measurements to the projected light exposure levels that artwork can sustain over its lifetime.
Table 1 Light Intensity Comparison Scanner exposure
0.0000009 to 0.0000386 Mlx-hrs
Year's worth of sunlight
115 to 290 Mlx-hrs
Day's worth of sunlight
0.3 to 0.8 Mlx-hrs
Day on a museum wall
0.000600 Mlx-hrs
Life of an artwork
4.3 to 10 Mlx-hrs
Evaluating Modern Flatbed Scanners
Seven different flatbed scanners were examined. The Umax Astra 1220S
was owned by the author and was thus examined thoroughly. The other
scanners were evaluated on the floor of the Seybold Seminars:
Publishing 98, in San Francisco, September 1-4, 1998, with the help
of several presenters and/or session leaders named in the credits
below.
The data was gathered using the following equipment combined into a time-based light measurement instrument:
The measurements were made at 1-second intervals over the scan period. The sample rate was a little too coarse, but it made the data acquisition and processing manageable. Measurements made at 10 samples per second (100 ms intervals) varied by 0.1± from the slower rate, making the variation of the 1/sec measurements about ± 10%.
Table 2 shows that exposures from typical modern scanners ranged from 0.9 to 38.6 lx-hrs (lux-hours). Other scanners being sold today may vary by 10-25%, but not by an order of magnitude (100%). The average exposure was 11 lx-hrs, which is 1-2% of a daily exposure on a museum wall, or 0.000011- 0.000026% of an object's predicted life. The latter assumes that 4.3-10 Mlx-hrs are realistic estimates for an average work on paper, as noted in Table 1..
The measurement protocol used in this investigation was 600 dpi resolution, 36 bit color at the Dmax of the unit (shown in bold on Table 2). Lower resolution and bit levels were included for purposes of comparison. Color bit levels higher than 36 bit represent the lowest bit level the operator could achieve for the unit. It was incorrectly assumed that all units using the same lamp would have the same output within a line. This was found to be false only after the Microtek unit was evaluated. Unfortunately only one Microtek unit was evaluated, mistakenly.
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The shapes of the curves created when light output (Lux) was plotted against time varied markedly for scanners within a manufacturer's line and at different scanning resolutions from the same machine. Several of the lower priced units used what appeared to be proprietary double-pass, and possibly triple-pass, scanning protocols to increase scan quality to very good effect. Several curves have steps along their slopes, some with peaks and troughs at the beginning and end of the steps.
The Heidelberg Topaz iX is possibly the best CCD flatbed scanner available, and has the highest lux-hour number. It is capable of 4.0 Dmax, 5080-7620 dpi optical resolution at 48 bit color (16 bit per channel of RGB). It costs approximately $50,000, and takes its time making the best possible scan. Color accuracy, gamut, and sharpness were seen to be superior; the quality is also evident from the perfect Gaussian shape of the Light vs. Time curve (not shown).
UV Light Data
Data on UV (ultra violet) light was not gathered because it was
too costly and not considered as
significant.(8) Sensitive artifacts are more
vulnerable to the greater amount of visible light than to UV
radiation alone. UV light represents about 3% of daylight, indoor
(9). Thus, the effect of visible light is
much greater than UV radiation for sensitive materials. However, UV
does cause faster and greater damage to more light-stable materials.
The intensity of scans is so low that even if the UV component were
5-10% of the total light energy, it would not represent a big effect.
Cold cathode lamps are a form of fluorescent illumination. Several fluorescent lamps commonly used in cultural institutions for illuminating artifacts have approximately 0.7-2.4% of their light radiation composed of UV.(10)
Conclusion
The claims made by some experts on the intensity of flatbed scans
are overstated. Most scans will be from 1-15 lx-hrs, which is a
minuscule fraction of the useful life of a document or artwork.
Issues associated with a document's physical protection during
scanning, such as damage to spine or friable paper, should be of
greater concern to librarians, archivists, or curators when flatbed
scanners are used for digitization. Digital cameras may be a better
tool for digitizing material with high sensitivity to physical
damage. Flash units would be the desired form of illumination. Normal
"hot lights" used in copy stand photography can generate radiant heat
that will dry and expand paper temporarily, causing pages to curl,
which will distort the image during photography. Incidentally, the
level of illumination using "hot lights" on the copy stand could be
much greater than the intensity of a flatbed scanner. Flash
illumination has a very short duration, 1/1000-1/4000 of a second;
thus, the lux-hrs are very low.
Acknowledgements
This work would not have been possible without the assistance of
several manufacturers' representatives:
Notes
(1) For general information on cold cathode type lamps see:
http://lighting-inc.com/manufacturers/nationalcathode/whatis.html
(2) Breitenbach, A. "Inside the Charged Coupled Device," Digital Camera, Vol. 1, No 1. July 1998, pp. 54-55 & 58; Dierickx, B. "The Human Eye Versus Silicon." http://www.imec.be/bo/ccd/evs.html, 4/6/97.
(3) Calculated for the Bay Area/Silicon Valley region, excluding foggy coastal areas, such as San Francisco and Santa Cruz. The southwest US ranges from 171-290 Mlx-hrs yearly exposure; East Coast about 171-230 Mlx-hrs; and the northern US and Canada 115-170 Mlx-hrs. Europe ranges from 115-230 Mlx-hrs yearly. See Thomson, G., The Museum Environment, Butterworth-Heinemann, New York & London, 1994, 2nd edition, pp. 168-174.
(5) It is assumed that an artwork will have a useful life of about 500 years. Standard museum light level for works on paper is 50 lux (5 foot-candles) for 12 weeks (6-day week, 12-hour day) every 3-5 years; about 43,000 lux-hrs per exhibition. The works do not need to rest after display, the waiting period is intended to serve as a guideline for full life and reflects standard museum practice where a work is used in a exhibition every 3-5 years, or so. When the math is run, an artwork will live through about 100 exhibitions over 500 years, if displayed 12 weeks every 5 years, or about 300 years if exhibited every 3 years. The Reciprocity Law applies to light. The numbers can be pushed around at will: one could exhibit at 1 Mlx-hr and then put the artifact in the drawer for 100 years; or exhibit for only 6 weeks (21,500 lx-hrs), then the artifact would last about 1000 years.
(6) Colby, K.M. "Suggested Exhibition Policy for Works of Art on Paper," J. IIC-CG (Journal of the International Institute for Conservation, Canadian Group), Vol. 17, 1992 pp. 3-11; Colby, K.M. "A Suggested Exhibition/Exposure Policy for Works of Art on Paper", http://www.webcom.com/~lightsrc/policy1.html (1998).
(7) "Just perceptible change" seems to be a very low threshold;
0.1 d would seem a more
reasonable threshold. This would reflect the reality of use and the
fact that density is logarithmic. If just perceptible change is the
defining limit, then collections managers will be tempted to go
beyond the recommended light levels, because some fading over time
(500 years) is normal and acceptable. Pegging the change at a low
(0.1 d ), but reasonable
amount, makes stretching the light level recommendation less
acceptable.
(9) UV is 3% of the total light output from the sun that reaches the Earth's surface through standard window glass. UV is 4.5% of total sunlight outdoors. See Thomson, G., pp. 168-174.
(10) Ibid., Thomson, p. 168. Standard tungsten bulbs have 0.67% UV component.
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Highlighted Web Sites Arts and Humanities Data Service (AHDS) The AHDS Web site, mentioned in previous RLG DigiNews announcements, has been very active recently, providing several new reports on digital imaging and digital preservation. Funded by the Joint Information Systems Committee of the UK's Higher Education Funding Councils, the AHDS aims to promote awareness in the scholarly community about the importance and value of electronic information, and provides guidance in its effective creation and use. In its attempt to establish a framework of strategies and standards for developing, managing, and distributing scholarly digital collections, the AHDS supports research and explorations, and makes the reports of these studies available via its Web site. The site also provides access to information about digital resources, services, and projects of general interest to the arts and humanities community. We suggest that you check out the "What's New" link to view a list of new and updated documents. |
Calendar of Events
Electronic Copyright
And Digital Licensing: Where Are The Pitfalls?
November 5-6, 1998
To be held in Rome, Italy, this international conference and workshop
is jointly organised by the Italian Library Association, EBLIDA
(European Bureau of Library, Information and Documentation
Associations) and ECUP+ (European Copyright User Platform) and can be
seen as a follow-up to the successful Copenhagen conference which was
held in February 1998. The conference will provide a forum to present
the results of three years successful work under the ECUP+ concerted
action.
Rights
Management, Copyright & the New Age of the Digital Image
November 10, 1998
Sponsored by Computers in Teaching Initiative in Art and Design,
this workshop (University of Newcastle, United Kingdom) is
recommended for anyone who is confused about and wishes to understand
copyright. The workshop will also encourage debate, and offer an
opportunity to exchange views and opinions with colleagues about
copyright and rights management issues.
Managing a
Digital Imaging Project
November 11, 1998
This workshop is sponsored by the Technical Advisory Service for
Images, and will be held at the University of Newcastle, United
Kingdom. It is recommended for anyone who wishes to learn about
project management within the context of a digital imaging project,
and for those who are currently working on an imaging project.
Convergence:
Culture and Policy in the Digital Age Conference
November 18-20, 1998
This conference to be held in Brisbane, Australia is sponsored by
the Australian Key Centre for Cultural and Media Policy. It will
focus on the realities and implications of digital convergence in the
cultural field. Attendees will bring together national and
international expertise in the fields of the arts, broadcasting,
collecting institutions, education, government, industry, information
technologies, and intellectual property to discuss issues of common
concern, and to provide settings for effectively engaging the
challenges of the digital age in a strategic way.
Call for
Papers: Joint International Conference of the ACH/ALLC in 1999:
Digital Libraries for Humanities Scholarship and Teaching
Deadline: December 1, 1998
The ACH (Association for Computers and the Humanities) and ALLC
(Association for Literary and Linguistic Computing ) invite
submissions on any aspect of humanities computing, defined broadly as
the use of computing methodologies in humanities research, teaching,
or archives. Submissions are encouraged from scholars, teachers,
librarians, museum professionals, editors, and publishers involved in
the creation, maintenance, delivery, and use of digital information.
The conference will be held June 9-13, 1999 at the University of
Virginia in Charlottesville, Virginia.
Call for Papers:
ICCC/IFIP Third Conference on Electronic Publishing
Deadline for Abstracts: December 7, 1998
This third conference sponsored by ICCC (International Council
for Computer Communication ) and IFIP (International Federation for
Information Processing) will be held in Ronneby, Sweden May 10-12,
1999. The theme is: Redefining the Information Chain - New Ways and
Voices. Papers on technical, human, and economic aspects of
electronic publishing will be welcomed. The conference will be
concerned with electronic publishing both for specialist audiences
and for the general public. There will be two tracks. The first track
will concentrate on technical issues, such as file formats,
protocols, networking, and retrieval techniques. The second track
will include case studies, presentations of projects, and
presentations of implemented electronic publishing in public and
scholarly libraries, art galleries, and museums.
Call
for Papers: Knowledge: Creation, Organization and Use:
ASIS 1999 Annual Conference
Deadline: December 15, 1998
To be held in Washington, D.C. November 1-4, 1999, and sponsored
by the American Society for Information Science, this conference will
look at current knowledge creation, acquisition, navigation,
correlation, retrieval, management, and dissemination, their
implementation and impact, and the theories behind developments.
AMIGOS Imaging Workshop
December 9-10, 1998
This two-day workshop to be held in Waco, Texas will provide an
overview of digital imaging, and will give participants a concrete
demonstration of the technology and process of imaging and the effect
these have on the creation of high quality digital images. The
workshop will cover the selection of appropriate materials,
guidelines and benchmarks for image quality, file formats, headers,
and compression.
Announcements
Digitizing
Legacy Documents: A Knowledge-Base Preservation Project
Available as a preprint over the Web, this paper describes a
production system to scan all of Fermilab's scientific and technical
reports going back to 1972, to convert them into Portable Document
Format (PDF), save them to a server for WWW access, and write them to
CDs for distribution. The project was funded by a 1998 Educate and
Automate grant from the Illinois State Library.
EC
DECOMATE II
The Telematics for Libraries funded project DECOMATE II: Developing
the European Digital Library for Economics, finished its
specification phase in August 1998. The report includes an analysis
of digital resources, the scope of Decomate II contents, and the
design of the user study.
Dublin Core
Metadata for Resource Discovery
A description of the Dublin Core Metadata Element Set has now been
published as Internet Engineering Task Force Informational RFC 2413.
This is the specification of the 15-element Dublin Core metadata set,
and the first in a series of planned Informational RFCs on the Dublin
Core.
The Metadata
Working Group
For the past few months, an international (mainly US/UK) group has
been working on the question of what metadata is required in the
digital environment to support unique identifiers, such as the
Digital Object Identifier (DOI), and to make possible the electronic
identification, retrieval and trading of intellectual property.
Sponsored by EDItEUR ( European Group for Electronic Commerce in the
Book and Serials Trade), this UK based organization has been active
in creating Edifact (Electronic Data Interchange For Administration
Commerce and Transport). An invitation is being extended for more
participants in the work. Discussions are carried on mostly via an
e-mail discussion group sponsored by the
International DOI Foundation. Signup
instructions are available on the Website .
ITEM (Image Technology in
Museums and Art Galleries Knowledge Base)
This is an international searchable text and image information
knowledge base detailing hypermedia publications and resources,
primarily about the visual arts. Published in association with CIDOC
(the Documentation Committee of the International Council on
Museums), ITEM includes multimedia publications, art gallery and
museum image databases, art auctions, photo libraries, and
information on art theft. The site also includes a collection of Web
links to other sources.
Automatic
Cataloguing and Searching Contest
The Fritz Kutter-Fonds Foundation encourages work in information
processing and applied computer science. The foundation is sponsoring
a contest for innovative methods in automatic cataloguing. In this
contest, the foundation is looking for new approaches that provide
good search functionality at significantly lower cost by avoiding the
expensive manual generation of metadata.
Digitization
Lessons Learned in First Round of Library of Congress/Ameritech
National Digital Library Competition
This useful survey of some of the lessons learned from the
1996-97 winners of the Library of Congress/Ameritech National Digital
Library Competition is based on the tracking reports of implemented
projects submitted by awardees.
IMLS Announces First National
Leadership Grants
The Institute of Museum and Library Services (US) has announced
41 grants totaling $6,487,750 for its first National Leadership Grant
awards. These awards will support library projects that address
education, research, preservation, and library-museum partnerships.
FAQs
Question:
My institution is getting ready to embark on its first digital
imaging project, and we are interested in finding information on
legal issues, such as copyright and licensing. Could you suggest any
Web sites that offer introductory information on these issues?
Answer:
Increasingly libraries and other cultural institutions find
themselves struggling with the legal implications of scanning and
providing Web access to resources under their care. The popularity of
this topic is evident when one searches the Internet. There are quite
a few Web sites providing novice and advanced-level information on
copyright and privacy issues. Nevertheless, most of them stress the
fact that the materials presented on their sites are not intended as
legal advice, and do not replace consulting qualified legal staff at
the institutional level. It should also be noted that laws and
regulations vary from country to country and even from one locality
to another.
Here are some of our favorite US Web sites that focus on legal issues in the digital domain, and have been kept up-to-date:
Copyright
and Image Management
This site is quite valuable as it specifically focuses on
copyright issues pertaining to digital image collections. Maintained
by Georgia Harper from the University of Texas System, it aims to
translate the fair use and display rights that apply to text-based
materials to the imaging world. It compares print and electronic
collection issues, and also includes a copyright crash course on
different information formats such as images, video, designs, and
illustrations. The site also covers and assesses the Guidelines for
Educational Uses of Digital Works that resulted from the Conference
on Fair Use (CONFU), and provides "Rules of Thumb" in interpreting
them.
Licensing
Digital Information: A Resource for Librarians
Developed and maintained by the Yale University Library and the
Council on Library and Information Resources (CLIR), the goal of this
Web site is to offer information and useful starting points to
provide librarians with a better understanding of the issues raised
by licensing agreements in the digital age. In addition to general
information, it includes an inventory of national site licensing
initiatives and other licensing resources. Another noteworthy
component of this site is the licensing terms vocabulary, which
includes definitions of words and phrases commonly found in licensing
agreements. This site is also home to the archives of LIBLICENSE-L,
which is an Internet discussion list on the topic of electronic
content licensing for academic and research libraries.
Copyright
Management Center (Indiana University)
Although the primary goal of this site is to assist the Indiana
University community in dealing with copyright issues in the creation
of original works and in the use of existing copyrighted works, it
also provides a useful online copyright tutorial. The purpose of this
tutorial is to "help educators move away from the fearful image of
copyright as an annoying or threatening beast and to work with
copyright while maintaining focus on academic pursuits." The tutorial
is delivered in a series of short email messages (approximately three
per week) via a discussion list.
National
Initiative For A Networked Cultural Heritage (NINCH): Copyright, Fair
Use and Licensing in A Digital World
NINCH is a coalition of cultural organizations joined to ensure
the greatest participation of all parts of the cultural community in
the digital environment. One of the emphases of the initiative
focuses on copyright-related issues. The Web site provides links to
both US and international copyright, licensing, and fair use
legislation related to digital resources.
Copyright
and Multimedia Law for Webbuilders and Multimedia Authors
This site, which is maintained by Karla Tonella from the
University of Iowa [clarification note added 27 August 1999:
original text stated the author was from Iowa State University],
provides links to several other copyright-related sites
such as Cyberlaw Encyclopedia, Multimedia Law, Cyberspace Law Center,
and Copyright Website. Its value is in gathering a variety of useful
copyright resources under a single Web page.
RLG News
RLG and AMICO Offer Licensed Access to Art Images
RLG is the testbed
distributor of the AMICO Library. The
AMICO Library consists of descriptions, images, and related
documentation of works of art from 23 museums. The RLG access system
offers sophisticated searching of the descriptions, and brings
results to the users in a variety of ways: the brief display as short
descriptions with thumbnail images (with options for text-only or
image-only display); the full record with a larger image; and a full
image (in a choice of two sizes) with image metadata and options for
downloading. Each of the displays features licensing information and
a link for further rights information.
The AMICO consortium is addressing access and licensing issues; the 17 university testbed users are investigating educational uses of the resource; and RLG is building a larger Museum Resources service, of which the AMICO Library will be a part. The service will be generally available in September 1999.
Hotlinks Included in This Issue
Feature Articles
AHDS study:
http://ahds.ac.uk/manage/framework.htm
AS 4390:
http://www.naa.gov.au/
CEDARS Project:
http://www.leeds.ac.uk/cedars/
Conference Web
Site (UK and Europe):
http://www.thames.rlg.org/preserv/joint/
Conference Web Site
(US): http://www.rlg.org/preserv/joint/
Corbis:
http://www.corbis.com/
eLib Programme:
http://www.ukoln.ac.uk/services/elib/
INSAM:
http://www.insam.mus.org/information/index.html
Kurturarw3:
http://kulturarw3.kb.se/html/projectdescription.html
Making of
America 2 (MOA2) White Paper, Version 2.0: Metadata Section:
http://sunsite.Berkeley.EDU/moa2/wp-v2.html
National Initiatives
and Coordination: http://www.nla.gov.au/niac/niac.html
National
Library's PANDORA project:
http://www.nla.gov.au/policy/plan/pandora.html
National Preservation Office at the
British Library: http://www.bl.uk
PANDORA
Project: http://www.nla.gov.au/policy/plan/pandora.html
PreWeb:
http://kulturarw3.kb.se/html/preweb.html
RLG's Working
Group on Issues of Preservation Metadata:
http://www.rlg.org/preserv/presmeta.html
RLG:
http://www.rlg.org/preserv/index.html
The Royal Library:
http://www.kb.se
Strategic Policy
Framework for Creating and Preserving Digital Collections:
http://ahds.ac.uk/manage/framework.htm
Summary of
Models for Preservation Metadata:
http://users.ox.ac.uk/~cedars/Papers/aiw01.html
The Swedish National Archives:
http://www.ra.se
Highlighted Web Site
Arts and Humanities Data Service
(AHDS): http://ahds.ac.uk/
Calendar of Events
AMIGOS Imaging Workshop:
http://www.amigos.org
Call for Papers: ICCC/IFIP
Third Conference on Electronic Publishing:
http://www5.hk-r.se/elpub99.nsf
Call for Papers:
Joint International Conference of the ACH/ALLC in 1999: Digital
Libraries for Humanities Scholarship and Teaching:
http://www.iath.virginia.edu/ach-allc.99/
Call for
Papers: Knowledge: Creation, Organization and Use: ASIS 1999 Annual
Conference: http://www.asis.org/Conferences/am99call.html
Convergence:
Culture and Policy in the Digital Age Conference:
http://www.gu.edu.au/gwis/akccmp/Convergence_conf.html
Electronic Copyright And
Digital Licensing: Where Are The Pitfalls?:
http://www.kaapeli.fi/~eblida
Managing a
Digital Imaging Project:
http://www.tasi.ac.uk/events/events1.html
Rights
Management, Copyright & the New Age of the Digital Image:
http://www-ctiad.adh.bton.ac.uk/ctiad/workshops/
Announcements
Automatic
Cataloguing and Searching Contest:
http://www.kutter-fonds.ethz.ch/contest99.html
Digitization
Lessons Learned In First Round Of Library Of Congress/Ameritech
National Digital Library Competition:
http://memory.loc.gov/ammem/award/lessons.html
Digitizing
Legacy Documents: A Knowledge-Base Preservation Project:
http://fnalpubs.fnal.gov/archive/1998/tm/TM-2056.html
Dublin Core Metadata
for Resource Discovery:
ftp://ftp.isi.edu/in-notes/rfc2413.txt
EC DECOMATE
II: http://www.bib.uab.es/project/eng/decomat2.htm
IMLS Announces First National
Leadership Grants: http://www.imls.fed.us/
International DOI Foundation:
http://www.doi.org
ITEM (Image Technology in Museums
and Art Galleries Knowledge Base): http://item.suffolk.ac.uk
Metadata Working
Group: http://www.doi.org/maillist-info.html
FAQs
Copyright
and Image Management:
http://www.utsystem.edu/OGC/IntellectualProperty/image.htm
Copyright
and Multimedia Law for Webbuilders and Multimedia Authors:
http://www.arcade.uiowa.edu/proj/webbuilder/copyright.html
Copyright
Management Center (Indiana University):
http://www.iupui.edu/it/copyinfo/home.html
Licensing
Digital Information: A Resource for Librarians:
http://www.library.yale.edu/~llicense/index.shtml
National
Initiative For A Networked Cultural Heritage (NINCH): Copyright, Fair
Use and Licensing in A Digital World:
http://www-ninch.cni.org/ISSUES/COPYRIGHT.html
RLG News
AMICO consortium:
http://www.amico.org/home.html/
AMICO Library:
http://www.rlg.org/amicolib.html
Museum
Resources: http://www.rlg.org/strat/projmusres.html
Publishing Information
RLG DigiNews (ISSN 1093-5371) is a newsletter conceived by the members of the Research Libraries Group's PRESERV community. Funded in part by the Council on Library and Information Resources (CLIR), it is available internationally via the RLG PRESERV Web site (http://www.rlg.org/preserv/). It will be published six times in 1998. Materials contained in RLG DigiNews are subject to copyright and other proprietary rights. Permission is hereby given for the material in RLG DigiNews to be used for research purposes or private study. RLG asks that you observe the following conditions: Please cite the individual author and RLG DigiNews (please cite URL of the article) when using the material; please contact Jennifer Hartzell at bl.jlh@rlg.org, RLG Corporate Communications, when citing RLG DigiNews.
Any use other than for research or private study of these materials requires prior written authorization from RLG, Inc. and/or the author of the article.
RLG DigiNews is produced for the Research Libraries Group, Inc. (RLG) by the staff of the Department of Preservation and Conservation, Cornell University Library. Co-Editors, Anne R. Kenney and Oya Y. Rieger; Production Editor, Barbara Berger; Associate Editor, Robin Dale (RLG); Technical Support, Allen Quirk.
All links in this issue were confirmed accurate as of October 12, 1998.
Please send your comments and questions to preservation@cornell.edu.