DPL was a pioneer in library photo imaging technology by partnering with CARL Corporation to integrate their Western History collection into Everybody's Catalog in 1995 (see http://www.carl.org/news/ photo.html). Everybody's Catalog photo imaging is still uniquely powerful for providing access to high resolution images for detailed study, but it's only available inside the library. With CARLweb, researchers anywhere can access DPL's outstanding collection.
The CARLweb photo imaging interface displays thumbnail images in the brief display, allowing the user to browse the images retrieved without going to the full bib record.
DPL's collection contains more than 600,000 photographs of Colorado and the American West. So far, 50,000 images have been put online. DPL researchers study each photograph, related materials, and reference works, then catalog each image in MARC format. Catalogers use subject classifications from the Library of Congress Thesaurus of Graphic Materials, noting content, size, condition, and any notes associated with the photograph. Related photographs are cross referenced and hyperlinked.
The photos are scanned at DPL's imaging center and stored in four formats. A very high resolution “Archive” image of each photograph is stored on servers at DPL in TIFF format and can be used to produce photo-quality reproductions, available to the general public for a fee. High resolution “Display” files, in JPEG format, are available for viewing in-house with Everybody's Catalog. Low resolution “Thumbnail” images are produced for display in the brief record in CARLweb or Everybody's Catalog, and a medium resolution “Preview” file is made and stored in JPEG format. Thumbnail, Preview and Display files are generated in a batch process from the Archive file. All image files are stored on CD-ROM.
When scanning the materials, the earliest possible generation of the photographoften the negativeis used, but digital re-touching is not permittedflaws such as cracks or stains are retained.
DPL's online collection can be viewed at http://gowest.coalliance.org. For more information about the project, see http://gowest.coalliance.org/highlights/faqs.htm. If you are interested in implementing a photo imaging project in your library, contact your client representative or Paula Busey, CARLweb Product Manager, at pbusey@carl.org.
