Understanding Records Management: Digital Imaging of Backfiles

One of the most important choices you will face is whether to convert your older files to images. Because backfile conversion will greatly increase your costs and place large demands on your staff, it needs to be carefully considered. As a rule, older records are likely to see less use than more recent ones. With this in mind, it may be possible to convert only those backfiles that receive repeated use and leave others in their original format. If you conclude that backfile conversion is necessary, you should examine the possibility of having it done by an outside contractor rather than doing it in-house. Contractors may be able to complete the process in less time and without interrupting your normal business routine. They will not, however, be able to work without your input. A successful document conversion procedure demands knowledge of the records and the functions of your organization. It is likely that you or a member of your staff will need to be available to provide assistance and supervision. KDLA provides backfile conversion services on a cost recovery basis. For more information, see Scanning and File Conversion Services.

Ensuring the long term accessibility and usability of records stored as digital images is largely dependent on how digital imaging systems are designed, implemented, managed, and migrated. A common misperception is that imaged records will be available as long as the physical media used to store the images last. Preservation of media is only one element that ensures long-term accessibility to records. The key to maintaining usable imaged records for long periods is the ability to transport the records, access tools, and required system functionality between hardware platforms, software platforms, and storage media over time. For a detailed explanation of imaging preservation issues, see: Ensuring the Long-term Accessibility and Usability of Records Stored as Digital Images: Guidelines for State and Local Government Officials.

Because optical storage technologies are evolving so quickly and because the challenge of managing those recordkeeping technologies over time is substantial, the Kentucky Department for Libraries and Archives has issued Policy Memorandum on Optical Storage of Public Records PM 96-1. This document describes the conditions by which records may be maintained in an image-only format. Standards for Conversion of Digital Images to Microfilm Format (PM 99-1) prescribes the format for the creation of microfilm from imaged documents.

All images should be stored in or convertible to compression formats identified in the IT Enterprise Architecture and Standards. Currently, the standard requires use of, or an ability to convert to, CCITT Group IV. Tagged Image File Format (TIFF) is the best example of this type of file for long term storage. Other types of image formats (JPEG and GIF) could be used for display on the web, but TIFF is the best medium for long term storage.
One advantage of storing digital images is that the files can be shrunk, or compressed, and therefore take up less memory. The greatest challenge in compressing files is that you may lose data. Compression options vary in their degree of data loss. Some are intentionally "lossy ," such as the JPEG format, which relies on the human eye to fill in the missing detail. This loss of data is why the JPEG format, while very useful for the display of images, should not be used as a primary storage format. The state standard CCITT Group IV compression is a " lossless " compression algorithm in which far less data is lost upon compression, although some data might still be lost.