CENDI/96-2
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Information International Associates, Inc.
Oak Ridge, Tennessee
April 1997
Chair - Barbara Bauldock (DOE/OSTI)
DOE/OSTI - Jannean Elliott*, Ken Hohenbrink,
Norm Smith
DTIC - Helen Viel*, Susan Ruddle
NASA - Roland Ridgeway*, Roy Stiltner, Patricia Baxter
NLM - Lou Knecht*
NTIS - Tom Pennington*, Roger Counts,
Sue Feindt
* Indicates primary contact.
CENDI's mission is to help improve the
productivity of Federal science- and technology-based programs
through the development and management of effective scientific
and technical information support systems. In fulfilling its
mission, CENDI member agencies play an important role in helping
to strengthen U.S. competitiveness and address science- and technology-based
national priorities.
| EXECUTIVE SUMMARY | 1 |
| 1.0 INTRODUCTION | 2 |
| 2 | |
| 2 | |
| 3 | |
| 3 | |
| 4 | |
| 7.0 QUALITY CONTROL | 4 |
| 8.0 MAINTENANCE OF GUIDELINES | 4 |
This document provides guidelines for the exchange of images among
the CENDI partners. It is meant to provide assistance for project
and technical staff seeking to import or export images. As the
CENDI agencies move toward electronic acquisition and distribution
of documents, the continued exchange of hardcopy and microfiche
documents does not fit into the electronic workflows envisioned
by the agencies. In order to promote the efficient sharing of
images, the CENDI Principals (July 16, 1996) requested that the
Information Exchange Working Group develop guidelines for sharing
images.
The standard format is compliant with the TIFF 6.0 Specification
with CCITT Group 4 compression. A TAR file is created for each
individual document and separated from the next TAR file on the
tape by an EOF mark. Each page of a document is stored as a separate
image in a separate file. The filename corresponds to the page
number or the order of the images within the document. The filenames
are eight digits in length, padded to the left with zeroes. Based
on this convention, the filenames can be computed easily, eliminating
the need to store the filenames elsewhere in the system, and providing
an easy way to ensure proper presentation order of the images.
The filename extension is ".tif", serving as an indication
of the viewer needed to display the file. For example, the filenames
are 00000001.tif, 00000002.tif, etc. The filenames for a document
are stored in a directory named for the document ID assigned by
the originating agency. In this way, the document can be manipulated
by the directory name rather than the individual filenames. The
unique document ID is also the link to the bibliographic record,
which records, if provided, are stored on a corresponding tape.
The preferred distribution medium is 8mm DAT. The tape includes
an internal directory file, external label, and transmittal report
that provide information regarding the filenames within each directory,
the number of image files and documents, the sequence number of
the tape, the total number of tapes being sent, the originating
agency, and the date or volume and issue of the announcement.
The minimum resolution for scanned images is 300 dpi. Higher
resolution may be used as necessary to achieve high quality images
or for specific image types. Care should be taken to provide the
best quality available from the original.
These guidelines were developed February 1997. They may be modified
as the technology changes and the sharing of images between CENDI
agencies increases production-level experience.
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This document provides guidelines for the exchange of images between
the CENDI partners. It is meant to provide assistance for project
and technical staff seeking to import or export images.
Many of the CENDI agencies have historically shared hardcopy and
microfiche formats of documents in order to reduce the redundancy
of acquiring, cataloging, and in some cases indexing documents
covered by one agency that are also relevant to another CENDI
agency's scope and coverage. As the CENDI agencies move toward
electronic acquisition and distribution of documents, the continued
sharing of hardcopy and microfiche documents does not fit into
the electronic workflows envisioned by the agencies. In order
to promote the efficient sharing of images, the CENDI Principals
(July 16, 1996) requested that the Information Exchange Working
Group develop guidelines for sharing images.
A focus group meeting with representatives from the Defense Technical
Information Center (DTIC), the Department of Energy Office of
Scientific and Technical Information (DOE OSTI) (Washington),
the NASA Center for AeroSpace Information (NASA CASI), the National
Technical Information Service (NTIS), and the National Library
of Medicine (NLM) was held on July 24, 1996. Representatives
from DOE OSTI in Oak Ridge, TN participated via videoteleconference.
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The standard format is compliant to the TIFF 6.0 Specification
with CCITT Group 4 compression.
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3.0 DIRECTORY AND FILE STRUCTURE
A TAR file is created for each individual document and separated
from the next TAR file on the tape by an EOF mark. Do not use
any "hard path" for the document directory.
The directory name is the unique document ID assigned by the originating
agency. Segregating the documents by directory facilitates moving
the document to a new disk or copying it to tape, since the manipulation
is by directory rather than by individual filenames.
The files containing the TIFF images for each page of the document
are stored within the directory. The naming scheme for the image
files is the image number within the document followed by the
".tif" extension. The image number is the sequence
of the images in the original document, padded to the left with
zeroes to create an eight-digit numeric. For example, a five-page
document has the image filenames 00000001.tif, 00000002.tif, 00000003.tif,
00000004.tif, and 00000005.tif. Gaps in the sequence of filename
numbers, such as those caused by blank pages in the original document,
are permissible as long as a numerical sort of filenames results
in the images falling into the correct sequence.
This naming convention is compatible with most computer systems.
(Note that this convention is not directly compatible with MS-DOS
systems if the document ID, i.e., the directory name, exceeds
eight characters.) In addition, the filenames are computed easily,
eliminating the need to store the filenames elsewhere in the system.
The filenames also indicate the order of presentation.
For example, create the tar files like:
tar cvf /dev/nrst0 documentID1_dir
tar cvf /dev/nrst0 documentID2_dir
.
. [where documentID1 and documentID2 are the unique ID's for the documents assigned by the distributing agency]
.
The listing resulting for tar tvf /dev/nrst0 is:
/documentID1_dir/00000001.tif
/documentID1_dir/00000002.tif
.
.
/documentID1_dir/end.tif [where end is the last sequential image number in documentID1]
EOF
/documentID2_dir/00000001.tif
/documentID2_dir/00000002.tif
.
.
/documentID2_dir/end.tif [where end is the last sequential image number in documentID2]
EOF
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4.0 CONNECTION TO BIBLIOGRAPHIC RECORDS
For exchange of new records, the full bibliographic records are
included on a separate tape. (This Guideline does not include
the specification for the bibliographic record.) The bibliographic
record has the same unique document ID used to name the image
file directory so that the two records can be connected by the
receiving agency.
The transfer of TIFF images for archival documents may be accompanied
by bibliographic records, depending on the agreement between the
agencies. If bibliographic records are included, they may contain
fewer elements than the full record. (These specifications will
be more clearly defined following future discussion of legacy
collections.) If images are being sent for bibliographic records
provided previously (i.e., the scanning of legacy documents),
these images are provided on a separate, specifically marked tape.
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Each tape includes a file containing the directory name and the
filenames within each directory. The name of this file is tape_toc.
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The preferred distribution medium is 8mm DAT. The external label
minimally identifies the originating agency, the type or classification
of data included, the date range (or announcement volume and issue)
for the selected records, the sequence of the tape and total number
of tapes in the set, and the date the tape was created.
A transmittal report or packing slip accompanies the tape on paper
or as an electronic file. The report minimally includes the agency
or database name, the date range or the announcement volume and
issue numbers for the documents selected, the date the file was
created, the number of files, the number of documents, the number
of pages (images), and the list of the filenames for each directory.
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The minimum resolution for scanned images is 300 dpi. Higher resolution
may be used as necessary to achieve high quality images or for
specific image types. While there are no quality standards for
images, care should be taken to provide the best quality available
from the original. Some guidelines include:
! Beware of "stray images" resulting from scanning on a flatbed scanner;
! The document must be viewable by a standard TIFF viewer that supports TIFF Group IV;
! 400-600 dpi resolution is
recommended for color and halftone photographs.
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These guidelines may be modified as the technology changes and
the sharing of images between CENDI agencies provide the CENDI
agencies with production-level experience. The CENDI Information
Exchange Working Group is responsible for periodic review and
update of these guidelines.
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