Charles W. Cushman Photograph Collection
  Indiana University Archives / Digital Library Program

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Digitization Process

The slides in the Charles W. Cushman Photograph Collection were outsourced to Luna Imaging, Inc.,, in Culver City, California for digitization. We purchased from Luna one master TIFF file and three sizes of JPEG derivatives (200, 600, and 1000 pixels on the long side) for each of the nearly 15,000 35mm slides in the collection. The master file specifications were as follows:

Master Image
File format:




Pixel dimensions:

ca. 3000 pixels on the long edge

Bit depth:

24-bit RGB color




Should match slide in its current condition. No "correction" should
be done. sRGB color profile should be embedded.

When we received the images back from the vendor, we subjected them to a rigorous quality control process. Scripts checked features such as resolution, pixel dimensions, bit depth, compression, and embedded color profiles for every image. 10% of the master TIFF images were visually inspected according to a variety of criteria, including color faithful to the original and orientation. A sampling of JPEG derivatives were also visually checked for appropriate compression levels.

The slides were shipped to Luna in three main batches of approximately 5,000 slides each, in intervals of about two months. A final, much smaller, shipment of slides to be rescanned as a result of our quality checks was sent after the final main shipment was received. The entire digitization process for the collection took 8 months. The Request for Proposals that we used to select the digitization vendor can be found at <>.