In terms of the capture of images, electronic text, and other formats, participating repositories will have the option of either: 1) completing scanning or other means of capture at the home repository or 2) submitting materials for capture at a central location. Regardless of capture location, participants will perform this activity according to predefined standards for archival master files. Participants will centralize and automate the production of compressed access images and watermarks.
On this topic, the National Archives and Records Administration provides its Guidelines for Digitizing Archival Materials for Electronic Access (1998). This resource along with Columbia University's "Technical Recommendations for Digital Imaging Projects" (1997) and Cornell's Digital Imaging for Libraries and Archives (1996) comprise a partial list of the materials that guide The University of Southern Mississippi Libraries as they endeavor to create digital images of sufficient quality to meet their objectives. They use the following guidelines for image capture and suggest the use of these same guidelines for partners in the Mississippi Digital Library.
Two sets of images should result from the digitization process. Though the primary goal is to provide electronic access to records, an off-line master set of images is created in anticipation of future needs and changing standards.
Imaging Standards for Archival Masters
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By default, materials are scanned at 24-bit depth (RGB-millions of colors). Black-and-white photographs and other materials with no color information may be scanned at 8-bit depth (256 shades of gray).
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By default, materials are scanned at 600 dpi to create a digital master.
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No restoration or other digital enhancements are performed on digital masters, except those necessary to match the appearance of the original materials. Digital master files are saved in uncompressed TIFF format.
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Digital masters are archived on DVDs, hard drives, and magnetic tape.
Imaging Standards for Derivative Images
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Derivative images are provided for Internet transfer and public use. Further derivatives may be produced if evaluation of the materials shows the need.
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Digital "submasters" are created of badly damaged materials through digital restoration in order to improve the usability of the materials. Materials will be evaluated on a case-by-case basis to determine if restoration is needed. In cases where materials are digitally restored, users will also be provided with a non-restored image, in order to give the user some idea of the condition of the original materials.
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Currently, our access files are primarily intended for screen display. To that end, 8-bit grayscale/24-bit color is used and digital images are resized to 600 pixels across the shortest dimension, 72 dpi, and saved in a JPEG format.
Please send
comments or questions to: info@msdiglib.net
© 2006 Mississippi Digital Library
URL:http://www.msdiglib.net
Last modified:
May 29, 2006
