Get Involved: The preservation manager should feel comfortable in joining with the technical experts, side by side, to develop the science. There are key questions to be answered and standards to be formulated. We must become proactive, recognizing that good preservation systems will only be developed when the preservation community takes an active role in the development process. We can build alliances with digital image vendors and information suppliers. We can educate the developers about preservation requirements and in turn, be educated about the technology. We can work with the technical experts to develop strong requirements and specification documents. We can set the tone for how these systems will evolve.
Understand the Technology: Preservation has developed quickly as a science, but some basic questions remain unanswered. Preservationists must weigh a variety of concerns when choosing a preservation format. In the parallel universes of micrographics and digital imaging, this is no easy task. Digital imaging is as misunderstood for preservation work as micrographics is commonplace. For instance, what is the minimum digital image resolution and greyscale combination that will satisfy the archival requirement for preservation? At what point will digital resolution be equivalent to film resolution? Does it need to be, or should the standard be changed to consider low-contrast page areas more? How can we influence vendors to develop the kind of high-resolution scanners, book scanners, high-bandwidth communications, etc., that digital image preservation work requires? Also, the matter of electronic media obsolescence and how it applies to archival storage is not well understood or generally accepted in terms of preservation economics or policies. Finally, the access, transmission and distribution requirements must be understood and evaluated, and their economic impact factored into the equation.
Minimize Risk: In the world of information science, technology travels faster than the speed of decision-making. Adopting an electronic publishing preservation strategy requires a tremendous investment of resources. A backlog of several billion pages awaits conversion now. Brittle research materials are deteriorating rapidly. And although a hybrid system is within sight, the vanishing documents will not wait. To minimize risk, a solution that uses today’s micrographics technology can and should be implemented, but this solution must anticipate the evolution of imaging technology. Preservationists should be aware of future access needs and consider the best methods for filming material for later conversion to digital formats. There is no doubt that digital imaging will play a large part in the future of preservation science.
Prepare for the Future
If the technology were available: For anyone considering a preservation imaging system, the design and implementation will likely take 12 to 18 months. By that time much of the required technology should be available. However, there is no reason to stand by and wait for technology to advance while delicate preservation materials continue to deteriorate. The important thing is to preserve materials in a recognized archival media for future generations. Film is currently recognized as that medium. As long as the film created is of high quality, and has a good low-contrast rendering of the halftones as well as a high-contrast rendering of the text, it can be scanned to digital when the complete preservation system is implemented.
The future digital solution: An effective preservation system should be designed so that the material is scanned at the optimal archival resolution with eight bits of greyscale per pixel. This high-resolution data will be further processed (as defined by the objectives for the project) using mathematical image enhancement filters, and finally be written to film to create an archival image that can always be accessed. A parallel process will convert the input data to a high-quality reduced resolution (adequate access resolution), enhanced, binary image that will be written to optical disc, which would guarantee improved access and excellent end-user print quality.
The long-range system: Twenty years from now we’re likely to see high-quality color page images stored using laser holography in a diamond composite storage medium that will cost less than one-tenth of a cent per page and last virtually forever. Compression algorithms will recreate pages from less than five percent of the data, and transmission costs will be 1/20th of current costs. The storage medium will be self-contained with built-in intelligence (the processor and the memory will be one), it will have the capability to monitor itself, correcting faults automatically, and when its error rates are projecting end-of-life, it will have the capability to schedule that it be rewritten. Since it has a built-in processor, it could also contain all the necessary software to recreate electronic page representation back into eye-readable form regardless of storage format. The question of obsolescence will become irrelevant. Systems will automatically monitor user access, read errors and storage costs of page images, and automatically migrate pages throughout the storage hierarchy depending on preprogrammed factors. Such a system will manage and preserve all digital materials automatically. If this seems far-fetched, remember that the PC is only about 10 years old.
An optimal mix: Today, according to a traditional definition film is the only truly archival medium. It will not become obsolete in the foreseeable future. Optical disc will be viewed as the permanent, low-cost, removable, random access storage media. Magnetic products (tape and disk) will continue to increase in storage capacity and reliability while decreasing in cost. Magnetic disk will provide temporary working storage for all work-in-process on all future image systems. Optical tape, too, bears watching. – In configuring the ideal image storage system, the knowledgeable designer will construct a hierarchy of storage that takes advantage of the strengths, access characteristics, longevity, and cost of each storage product to produce the greatest benefit at the least cost.