ON TECHNICAL AND LOGISTICAL ASPECTS OF PRESERVATION MICROFILMING AND DIGITISATION. The Issue of Tech

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ON TECHNICAL AND LOGISTICAL ASPECTS OF
PRESERVATION MICROFILMING AND DIGITISATION. The
Issue of Technological Adoption

• 15 April 2003
• LIBER Preservation Division
• Meg Bellinger
• Vice President, OCLC Digital Preservation
  Resources

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Digitization is not preservation!
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But neither is microfilming!
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Agenda

• Technological change and preservation
• Creation/capture for film and digital
• Storage for long-term retention

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The Pace of Technology Quickens
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DigitizationThe Technology Loop1
Leading Edge
Bleeding Edge
Digital preservation is here
Preservation microfilm is here
Operation Systems
Production Systems
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Selection for Reformatting

• Reformatting is the creation of an acceptable
  surrogate in order to
• Create a substitute for frequently used items to
  minimize handling of original
• Migrate information from actively deteriorating
  materials to more stable media
• The mere fact of creation of a surrogate is not
  preservation

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Life Expectancy (LE)

• BW Polyester-based photo films
• BW Acetate-based photo films
• Diazo films
• Polyester-based magnetic tape
• Digital optical media
• Digital data system

• ?? LE 500 yrs
• ?? LE 100 yrs
• ?? LE 100 yrs
• ?? LE 50 yrs
• ?? LE 30 to 200
• 18 - 36 months?

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Reformatting for Preservation

• Media/Media refreshment
• Capture/Creation
• Reproduction quality
• Metadata
• Storage for long-term retention
• Distribution (and control)

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Creation/Capture
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Making Preservation Microfilm
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About Preservation Microfilm

• 35 mm 16 mm, 105 mm fiche
• Mellon/RLG guidelines ISO standards
• Archive master, print master, service copy
• Planetary camera/lens systems
• Polyester base
• Technical targets
• Processing and chemical testing

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Advantages of Preservation Microfilm

• Archival medium with LE of 500 years
• Inexpensive, obsolescence-proof reader
• Predictable storage costs
• Unalterable
• Verifiable authentication process
• Excellent compaction
• Standards for creation and storage

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Continuous Tone Microfilm
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Color Microfilm
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Metadata

• Descriptive
• Shared in case of NEH requirements
• EROMM
• Administrative (QA records)
• Targets

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Making Digital Surrogates

• TIFF
• 1-bit
• 8-bit
• 24-bit
• JPEG
• GIF
• PDF

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About Digitization for Preservation

• DPI bit-depth
• DLF guidelines developing standards
• Multiple capture devices
• Archive master, surrogate
• TIFF for archive master
• Lossless compression
• Digital archiving

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Advantages of Digital Images

• Excellent record transmission access
• No degradation in successive copies
• Easily reformatted, manipulated
• Ability to enhance and link to enrichable metadata

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Technology Management
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Direct Scanning Options

• Equipment/Material Matrix

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Bitonal
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Grayscale
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Color
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Metadata

• Descriptive
• As yet no universal sharing mechanisms (Digital
  Registry)
• Structural
• Administrative
• Including preservation metadata (28 elements)

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Comparison on creation issues

• Microfilm
• Preparation intensive
• Capture devices straightforward but potentially
  unsupported
• Quality limited by current technology
• Color capture limited
• QA processes based on standards
• Rework is expensive
• Metadata creation simple

• Digital
• Preparation intensive, but
• Capture devices require significant cap.
  Investment
• Quality potential improving rapidly
• Superior color rendition
• QA standards are in development
• Rework is inexpensive
• Metadata creation complex

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Storage and Access
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Microfilm Storage
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Microfilm Storage

• Carrier is the capture media
• Acid-free containers
• Environmentally controlled vault
• Master and print master stored separately
• Master used once
• Susceptible to environmental conditions

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Digital Storage

• Carrier changes every 18 to 36 months.
• Carrier is device dependent so mass migrations to
  disc/tape preferred.
• File format subject to obsolescence
• Access systems subject to obsolescence
• Check-sum, virus check, metadata registration
  needed for submission, QA, and future processes

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Digital ArchiveDefinition

• Archive An organization that intends to
  preserve information for access and use by
  a
• Designated Community.
• OAIS - Reference Model for an Open Archival
  Information System

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Attributes of a Trusted, Reliable Digital
Repository

• Compliance with the Reference Model for an Open
  Archival Information System (OAIS)
• Administrative responsibility
• Organizational viability
• Financial sustainability
• Technological and procedural suitability
• System security
• Procedural accountability

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OCLC Digital Archive Cost of Development

• Staff Administrative - 2.4 million
• Design / pilot participant / development of
  requirements
• Software development / Integration
• Quality Assurance
• Hardware / Software - 675K
• Incremental hardware IBM SP servers, etc.
• Oracle, Symantec, IBM, etc
• Existing StorageTek hierarchical storage mgmt

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Unknown Costs of Digital PreservationJones and
Beagrie

• Managing technological changes over time
• Managing the proliferation of digital object
  types
• Lack of standardization in object types
• Defining what is essential

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Comparison on storage issues

• Microfilm
• Low risk - proper film base, processing, and
  physical environment
• Functionality uncompromised
• Passive storage minimal intervention
• Subject to physical damage
• Environment is static and HVAC dependent
• Low cost

• Digital
• Low to high risk - format and preservation
  metadata will determine risk
• Functionality will be compromised
• Active storage periodic mass intervention
• Subject to undetected loss
• Environment subject to obsolescence
• High cost

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• Thank you!
• Without preservation,
• there is no access.

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The Dilemma of Modern Media
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The Dilemma of Modern Media
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A Note on Digitization Preservation

• Digitization is not synonymous with preservation
• Digitization Of or relating to a device that
  can read, write or store information represented
  in numerical form.
• Preservation to keep or protect in unaltered
  condition maintain unchanged to prevent from
  decay or spoiling
• Digital Preservation - the various methods of
  keeping digital materials alive into the future

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Most librarians and archivists have accepted the
basic wisdom -- for now at least -- that digital
preservation depends upon copying, not on the
survival of the physical media (Lesk). But
copying, also referred to as "refreshing" or
"migration" is more complex than simply
transferring a stream of bits from old to new
media or from one generation of systems to the
next. Complex and expensive transformations of
digital objects often are necessary to preserve
digital materials so that they remain authentic
representations of the original versions and
useful sources for analysis and research (Task
Force on Archiving of Digital Information).
(Hedstom)