Digital imaging technologies have developed rapidly in the
last five years and will continue to develop into the next century. As no system is
generally regarded as a standard, it is important to acknowledge that certain proprietary
and non-proprietary standards will emerge as generally accepted by the industry and system
developers, integrator users, and records managers.
Because of the rapid changes in technology and the entry
and exit of firms in the marketplace, it is important to set base guidelines for the
responsible implementation of these technologies. The long-term nature of these digital
storage mechanisms and the significant value held in information assets of the various
agencies using these mechanisms motivates the adherence to international, national, and
industry standards relative to quality, storage, security, indexing, and access. Records
managers, systems administrators, program managers, and systems vendors need to be
familiar with current standards that are applicable to this area of information
technology.
This subject is discussed in detail in a technical report
issued by the Association for Information and Image Management (AIIM), The Use of
Optical Disks for Public Records. (AIIM TR25-1990).
The following are general guidelines of key areas of
interest to anyone working with imaging systems. Attention to these key areas will help
ensure successful implementation of systems and long-term responsibility for valuable
records.
System documentation: If you wish to maintain an effective
operation and continue to retrieve data as your operating environment changes over time,
you must keep full documentation of:
4.1.1 Hardware and software, including brand names, version
numbers and dates of installation, upgrades, replacements, and conversions.
4.1.2 Data structure and content, including the file layout
and data dictionaries.
4.1.3 "Enhancement" algorithms. These are
techniques for processing an image so that the result is visually clearer than the
original image.
4.1.4 Operating procedures, including methods for scanning
or entering data; revising, updating, or expunging records; indexing; backing up disks,
tapes, microfilm, etc.; testing the readability of records; applying safeguards to prevent
tampering and unauthorized access to protected information; and carrying out the
disposition of original records. In addition, to provide audit trails, you should document
procedures for logging and tracking. Full documentation of your operating procedures will
contribute to the legal acceptability of your records management program and will help to
make the data you produce from optical disks admissible as evidence in legal proceedings.
4.2.1 System Selection. When you are selecting a system,
strongly consider those with open rather than proprietary designs; open systems will give
you most flexibility when you are choosing equipment and will support interconnection,
information system integration, and information sharing.
4.2.2 Prepare specifications for hardware and software that
will require your vendors to continue to support and maintain their products.
4.2.3 Establish performance standards, incorporate them
into your specifications for hardware and software, and require vendors to support them
with a substantial performance bond.
4.2.4 Select systems that provide a scanning resolution
with enough density to produce a high-quality image. Scanners should have verifiable
quality and should be at a density of at least 200 dots per inch for textual documents and
300 dots per inch for engineering drawings, maps, and other documents. Calibration and
maintenance of the scanners should be as per the manufacturers recommended schedule.
Verification and inspection: Include visual inspection in your operational procedures to
verify the completeness and accuracy of the scanning process once documents have been
transferred to a disk.
4.2.5 Seek vendors who use standard rather than proprietary
compression algorithms to make future migrations of data more certain and reliable.
Imaging systems shall utilize the Consultative Committee on International Telegraphy and
Telephony (CCITT) Group 3 or Group 4 compression techniques without proprietary
alterations to the algorithm. If the use of a proprietary compression algorithm is
unavoidable, the system must provide a gateway to either Group 3 or Group 4 standards.
4.2.6 Require vendors to supply programs or provide
services to test the readability of your disks periodically. Government entities must
ensure readability of electronically stored images. A sampling of images from both primary
and backup storage media must be read annually to verify continued accessibility.
4.3.1 Indexing . When information is stored in a medium
that is not eye-readable, complete and accurate indexes are essential. Your system design,
therefore, must include provisions for appropriate indexing. When information will be
retrieved for many years from records that will be retained and used over a long period,
for example, you must develop and document indexes with future users in mind and include
in your operational procedures an index check for accuracy at the time the index is
created. The index storage method should be based on standard relational database
technologies with access using standard SQL queries.
4.3.2 Image headers. A standard image file header such as
TIFF or vendor supplied image file header should be used. If a proprietary header is used,
the system must provide a bridge to a non-proprietary header label standard such as
ANSI/AIIM MS53, File Format for Storage and Exchange of Images, or Bi-level File
Format: Part 1.
4.4.1 Labeling: Label disks, tapes, and other storage
containers with particular care since it is impossible to determine content merely by
looking at a disk or tape. Labeling is critical when the disk and its index are stored on
different media. Security copies shall be marked with appropriate external labels that
identify the government entity, system and software used, and any access restrictions. The
government entity shall maintain specific, detailed documentation of the contents and the
system specifications needed to access each backup tape or disk.
4.4.2 Back-up and storage: It is vital to make full,
frequent, and regular backups of optical records and magnetic indexes. Store your security
copies in secure and suitable facilities, preferably off-site, and since environmental
conditions for the storage of optical disks have not been established, follow the
manufacturers' specifications. Government entities shall adhere to the manufacturer's
recommendations for temperature and humidity conditions for the storage of security copies
of optical media. Backups for indexes, images, and other system components stored on
magnetic media or optical media should be housed in an area with stable environmental
conditions. Room temperatures (between 65 and 75 degrees Fahrenheit) and relative humidity
(40 to 45 percent) are the current standard for magnetic media. These should also be
observed for security copies of optical media.
4.4.3 Refreshment, migration, and conversion plans: Prepare
an appropriate plan for "refreshing" data and for migrating and converting
images and corollary indexes to new storage media as needed to preserve the records in an
accessible form. Data maintained on electronic media must be recopied onto new media at
least once every 10 years. << BACK MORE >>
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