International Congress on Archives 2004 pres 180 METCALFE C USA GSU 01 E Page 3
15
th
International Congress on Archives
The Genealogical Society of Utah
www.wien2004.ica.org
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Because patrons have direct access to the microfilm, damage can occur to the microfilm. Fingerprints and dirt
can damage the microfilm and reduce image quality. Improperly maintained equipment can scratch, tear,
wrinkle or scorch the microfilm. For every roll damaged a new copy must be made from the master microfilm
roll. Each duplication further damages and degrades the master copy's quality.
Microfilm has a limited tonal range that can render some documents unreadable. One of the characteristics of
microfilming is to increase the contrast of documents that are filmed. Contrast build-up can render some
documents nearly unreadable. This contrast build-up can be particularly difficult for documents that have a
limited contrast range between text and background densities.
There can be some concern about the environmental impact of microfilm developing and reproduction
processes. Some governments carefully monitor the effluence discharged from the microfilm developing
process. Special environmental considerations may need to be addressed in order to develop microfilm in certain
areas. The chemicals used to develop the microfilm, though generally considered to having minor environmental
impact, have raised some concerns.
With the advent of digital imaging several distinct advantages to conventional microfilm have been identified.
Starting with the capture of the digital images, the camera operator is allowed to view each image after capture.
This evaluation allows the operator to make adjustments to create the best image capture possible. Exposure,
light balance, reduction and all other aspects of the image capture can be modified to render the best image
possible.
Digital images can be manipulated in many different ways. The file formats can be changed. The files can be
compressed to save storage space. The images can be enhanced to improve readability. Security watermarks and
encoding can be added to the images. Images of good quality can be converted from color or grayscale to
bitonal images. These changes can be done individually or by batch processing. Digital images that are in color
can be changed to grayscale or bitonal images. This conversion is a method of saving space when a document of
less bit depth may still convey the information that the higher bit-depth document contained.
The digital images can be stored on a single computer and made available to a single user or the image files can
reside on a computer network. The computer network can deliver the images via a local area network, an
intranet or the Internet. Using the security features of most computer operating systems access to the images can
be broadly given or restricted as needed by the archive.
With the use of metadata, data about data, digital images can be accessed through integrated databases. These
databases can allow direct access to the images. The metadata can provide information about the images, their
content, technical information about the image and its capture, cataloging information and other administrative
information as needed.
Digital images can be encoded with security measures that will allow detection if the image has been modified.
Digital watermarks can be inserted on the image so that the image is readable but easily identified as an image
that belongs to a specific collection or carries a certain restriction. Because digital images are delivered via
electronic means, the user can be prevented from modifying or damaging the original image.
Digital images whether viewed one time or hundreds of times, maintain the same quality. Software can even be
provided that allows the user to view and manipulate the image to match their viewing preferences. Such
manipulation does not change the original file.
Digital technology also provides for access in remote locations. It will no longer be required that a user visit a
specific facility to view images, but they will be able to view images in the comfort of their own home or from
their work place.
Despite these advantages, digital imaging has several disadvantages compared to microfilming. New
technologies always have higher costs than those technologies that are more mature. Digital imaging equipment
tends to be more expensive than microfilming equipment. The digital files must be refreshed to new media
regularly. As computer hardware and software change, the images must be migrated to new formats. The
constant vigilance requires more financial dedication to digital preservation than microfilm requires. The storage
and preservation costs of digital can be ten times or more the cost of microfilm storage and preservation.
