Digital Imaging
Digital images are “electronic photographs” scanned from original documents. A digital image can accurately render the information, layout, and presentation of the original, including typefaces, annotations, and illustrations. Although digital-imaging technology has been available for some time, its widespread use in libraries began in the 1990s as technical advances led to improved image capture, lower costs, and greater accessibility.
Preservation professionals must ensure that the process of scanning does not damage an artifact, and that the scanning apparatus is appropriate to that artifact. For example, a fragile book should not be crushed down onto a flat-bed scanner. Preservation professionals should establish a conservation plan for each artifact or group of materials to be scanned. The plan of work would include the following:
• Training scanning technicians in the safe handling of artifacts, for example, wearing cotton gloves when handling photographs. Examining artifacts to identify damage risks such as fragile surfaces, tears, soiling, and mold or insect holes.
• The basic treatment of the artifacts by flattening, surface cleaning to remove soiling, the repair of tears and losses, and other treatments that are likely to cause damage to the artifact and reduce the quality of scanned images.
• Ensuring adequate security in the scanning area to protect artifacts from unauthorized handling and possible theft.
• Developing a post-scan housing plan to ensure stability of storage.
Ensuring that artifacts are in appropriate condition for handling by researchers. In some cases, the widespread appearance of digital images has stimulated interest in viewing original artifacts.
Digital images are much better than analog counterparts in terms of preservation and access. Digital images remain more faithful to the original, and from one copy to another. They also allow for flexible image capture, image enhancement, and continuing access through network distribution. Digital technology also holds potential for cost and space savings. Although digital imaging technology is promising, there are a number of important considerations for libraries and archives. These include:
• A rapidly changing technological base
• A transition period in which both the traditional and the new must be accommodated
• Legal constraints, including copyright
• Lack of standards
• Recopying, storage, and migration requirements
• Lack of institutional commitment and capability for archiving