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Commission on Preservation and Access

A Hybrid Systems Approach to Preservation of Printed Materials



1. Nugent, William R., “Applications of Digital Optical Discs in Library Preservation and Reference,” AFIPS–Conference Proceedings, Vol. 52, pp. 771-775.

2. Nugent, William R., “Research in Extending the Longevity of Information on Digital Optical Disks and Videodiscs,” Summaries: Electronic Imaging 86, Boston Mass., Nov. 86, pp. 790-795.

3. Ibid.

4. “National Archives Storage under Scrutiny,” Computerworld, Sept. 1, 1986, page unknown.

5. Gilheany, Stephen J., “Requirements for an All Digital Engineering Data Management System,” ATI Conference on Engineering Data Management, November 1983, pp. 2-7.

6. RLG Preservation Microfilming Handbook. Nancy E. Elkington, editor, March 1992. The Research Libraries Group, Inc.,

7. Bourke, Thomas, “Research Libraries Reassess Document Preservation Technologies,” Inform, September 1990, pp. 30-34.

8. Frank, John W., “Micrographics and Optical Disc–Friends or Foes?,” IMC Journal, July/August 1988, pp. 7-9.

9. Magnell, Glenn, “Micrographics and Optical Disk Technology: A Synergism in Information Management,” Image Update, Issue 11, June 1989, pp. 1-4.

10. Magnell, Glenn, Michigan Chapter AIIM meeting held on March 28, 1989.

11. Black, David, “The New Breed of Mixed-Media Image Management Systems,” IMC Journal, January/February 1989, pp. 9-13.

12. Moore, Frank A., “Spelling Out the Benefits of Imaging,” Inform, February 1990, pp. 29-32.

13. Willis, Don, “The Future of CD-ROM,” IMC Journal, Issue 2, March/April 1989, pp. 1 1-14.

14. Waters, Donald J., “From Microfilm to Digital Imagery,” a report published by the Commission on Preservation and Access, June 1991.

15. Andrews, Christopher, “Mastering The CD-ROM Mastering And Replication Process”, CD-ROM Professional, July 1991, pp. 17-18.

16. Lesk, Michael, “Image Formats for Preservation and Access,” a report published by the Commission on Preservation and Access, July 1990.

17. Datapro Research Group, “Datapro Reports on Document Imaging Systems,” Document Imaging Systems, February 1991, Vol. 2, No. 2, Section 5, pp. 3-4.

18. Datapro Research Group, “Datapro Reports on Document Imaging Systems,” Storage Technology & Products, June 1992, Vol. 3, No. 6, Section 8, pp. 12-27.

19. Ibid.

20. Hawken, William R., “Copying Methods Manual, Library Technology Program, American Library Association, 1966, p. 30.

21. Gordon, Max, “Dots and Spots: Taking Care of EP&P Halftone Requirements,” Electronic Publishing & Printing, November 1989, pp. 33-40.

22. Gilheany, Stephen, op. cit., pp. 10-11. (This paper and “Specifying a Digital Engineering Document Management System,” Nuclear Records Management Association Annual Symposium, September 1984, also by Stephen Gilheany, are valuable sources of information on both film and digital image document storage and retrieval systems and imaging questions in general.)

23. Gilheany, Stephen J., op. cit.

24. Gordon, Max, op. cit.

25. Ibid.

26. Smith, Ross, “‘G’ Controller for Graphics Grayscaling,” Publishing, March 1989.

27. Tapper, G.D., “Optical Discs–Standards,” IMC Journal, July/August 1988, pp. 41-42.

28. Courtot, Marilyn, “Opening the Berlin Walls,” Inform, March 1990, pp. 28-33.

Notes in Text

1. American Standard Code for Information Interchange

2. Throughout this document (unless otherwise noted) the page size used is a conservative measurement for the typical journal page of 8.5 X 11 inches or 93 .5 square inches. Since the typical book is only 5 X 9 square inches or 45 square inches, the storage space needed for a digital representation of hook pages at any resolution is about half of that required for the journal size page.

3. Continuing or enduring without fundamental or marked change.

4. A manual or computerized record that can be used to trace the type and origin of transactions affecting the contents of a document, record or file.

5. Measurement of the number of bits of data found to be in error when information is read off a storage medium.

6. Line-pairs per millimeter or lines per millimeter is a measurement of resolving power. The resolution test pattern is made up of black lines on a white background: the black lines and the white spaces are of equal width. A test pattern is said to be resolved if all five lines in both directions can be clearly differentiated.

7. Joint Photographic Expert Group

8. Type of electronic component that senses light. It builds up an electrical charge in direct proportion to the amount of light registered. The electrical charge can be read out for each individual element within he array to recreate an image line by line.

9. A method for representing graphic drawings such as blueprints or circuit diagrams with mathematical formulas (instead of in raster or pictorial format).

10. A method for reproducing an image (on, for example, a display), where individual picture elements (pixels) within the image are addressed and represented in both the horizontal and vertical directions. These pixels can be turned on and off in the binary (black or white) mode, the greyscale (usually 8 bits per pixel) mode, or the color mode (usually 32 bits per pixel). Regular television pictures are created in raster format.

11. A page description language developed by Adobe Systems. It is designed to translate text, line drawings and photographs created on a computer in conformance with its specifications into the proper bit-mapped dot pattern to recreate a page image on a screen or printer.

12. As mentioned earlier. a 5 X 9 inch typical book page is about half the size of the 8.5 X 11 inch page and therefore requires only about half as much storage space.

13. 300 * 300 (8.5 I 1) / 8 .5 = 526 KB divided by 2 for compression = 253 KB. We assume a compression ratio of only 2 to I because the high frequency black and white transitions present in all halftones do not compress well using CCITT run-length compression.

14. Capacity references are editorial comments by the author

15. Estimates are used here because service bureaus have had very little experience with preservation scanning. Estimates were arrived at by surveying service bureaus.

16. Kenney, A.R. & Personius, L.K., Update on Digital Technologies, Newsletter Insert, Commission on Preservation and Access, Nov. – Dec. 1991, Pages 1-6.

17. Source: Survey of other preservation micrographic sites by author.

18. Source: informal survey of preservation microfilming service bureaus by author.

19. Screen ruling, as used here, is defined as the distance between the halftone cells measured on an angle and from the center of each cell. The angle is about 45°. In this case, for example, a 7 X 7 cell would have a screen ruling of (square root of [7 squared + 7 squared]) = 9.9, equivalent to a 30 line screen; therefore the number of grey levels for this cell would be 300/30 squared + I = 101.

20. See M. Stuart Lynn’s glossary, page 47.

21. One terabyte is on trillion bytes or equal to 1,000,000 megabytes.

22. Media costs only, or equivalent media costs to store about 10 fairly complex 600-dpi binary image pages @ 100 Kbytes each.

23. Assumes that the CD-ROM is used for preservation purposes only and therefore, only one disc is created. Cost of mastering 1,500 / 660 MB / = $2.27 per MB. Cost per disc is much lower when CD-ROM is a distribution medium and numerous copies are produced. At 100 copies, the cost is reduced to about $0.02 per MB.

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