We are currently at a threshold in computer technology that will allow digitized images to be used cost effectively for the preservation and access of many types of visual materials.
Microfilming continues to be the main approach to preservation and will remain viable for years.
However, computer technology maintains a rapid pace of performance increase while continuing an exponential cost decrease. This is averaging a factor of two every two years.
Since the quality of digital images is now in the process of being demonstrated as equal or superior to the image quality of microfilm, it is clearly only a matter of time before digital techniques will be preferred for image storage and retrieval, even in a preservation environment.
Most of the objections raised to digital imaging relative to microfilm currently center on what are more properly termed media issues. As pointed out elsewhere in this report, the authors believe this is a misdirection of attention: more profit-motivated and moneyed parties are aggressively solving those problems.
Librarians, archivists and curators have had several roles in overseeing the archiving of visual materials to microfilm. These include monitoring the quality of the equipment at the time of image capture, requiring quality controls in the film processing steps, inspecting the results to some degree and then seeing to the maintenance of the physical medium via environmental and procedural policies.
Current concerns with respect to digital imaging include the following:
This report focuses on the central three questions from the list above: those dealing with capture characteristics, compression and logical formatting.