History of the American West

Building the Digital Collection

Since 1995, the Photography Department of the Western History/ Genealogy Department of Denver Public Library has been scanning photographs from its collection of over 600,000 photographs with the aim of using digital images as a substitute for study of the original photographic materials and to protect the original negatives and prints from handling. Since November 1995, images have been accessible on the Denver Public Library's internal network. In the 1996/97 round of the Library of Congress/Ameritech National Digital Library Competition, Denver Public Library received an award to support the scanning of 7,500 of these photographs and to allow access through American Memory to additional photographs that illustrate the history of the western United States. At the same time, Denver Public Library was working with the Colorado Historical Society and the Denver Art Museum and the Colorado Alliance of Research Libraries to develop a combined catalog for photographs that would support online access to the digitized images. This catalog was made accessible over the World Wide Web in December 1998.

Denver Public Library provides some answers to frequently asked questions about their Photodigitization Project.

Bibliographic records for over 30,000 photographs digitized by the Denver Public Library were delivered to the Library of Congress by the Colorado Alliance of Research Libraries for indexing as part of American Memory. These records, in the MARC format, include detailed subject headings. Denver Public Library delivered the corresponding thumbnail images. Copies of the same records are integrated into the vast WorldCat union catalog maintained by OCLC. The 856 field in each records includes a URL for the image as presented through Denver Public Library's own online photography collection. The same presentation is therefore integrated into American Memory, WorldCat, and Denver Public Library's own photography collection catalog. The URLs have the form http://photoswest.org/cgi-bin/imager?nnnnnnnn. The use of a dynamic program or script with a unique identifier number for each image as a variable parameter (rather than a static HTML page) ensures that Denver Public Library can modify its display or reorganize the underlying file structure without the need to modify the catalog records or worry about bad links in other copies of the records. This approach ensures a reasonable degree of persistence for the URL as an identifier and link.

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