P&P ONLINE CATALOG - FSA/OWI BLACK-AND-WHITE NEGATIVES

Digitizing the Collection

The images in the Farm Security Administration - Office of War Information collection (FSA-OWI) grew out of a special project to make preservation copies of deteriorating nitrate and diacetate negatives in the Library of Congress photographic collections. In the late 1980s, the original sheet film negatives began to be duplicated onto sheet film; in the mid 1990s, the 35mm roll film began to be copied onto 70mm roll film.

In the early 1990s, in order to produce a reference service videodisc, while the preservation reformatting proceeded, the Library produced an additional 35mm film copy of the negatives. The contractor, Stokes Imaging of Austin, Texas, produced the analog videodisc from the 35mm film in a two- step process. First, Stokes created a set of interim digital images with the moderate spatial resolution of 560x420 pixels. This set of digital images was archived. Second, the digital images were processed to create the analog video frames. Beginning in 1995, a new contractor, JJT, Inc., of Thorndale, Texas, reprocessed the interim digital images into formats suitable for archiving and Internet service. However, this reprocessing did not permit any increase in the resolution of the files.

The reprocessed digital files are, for the most part, what is presented in this online collection. The black-and-white images have a tonal resolution of 8 bits-per-pixel (256 shades of gray), while the color images have a tonal resolution of 24 bits-per-pixel (16 million shades). All have been compressed with the JPEG (Joint Photographic Experts Group) algorithm. Uncompressed versions of the images at the same resolution are also available online.

The "inline" thumbnail images for the Farm Security Administration - Office of War Information collection are in the GIF (Graphics Interchange Format) format and have a spatial resolution on the order of 150x150 pixels. The black-and-white images have a tonal resolution of 8 bit-per-pixel. These are the images displayed with the bibliographic records.


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Library of Congress
(February 1, 2006)