Creating Archival Master Files

Definition of the Archival Master File

The Archival Master File is a high-quality file produced directly from the Capture File that represents the original object as accurately as possible and is used for long-term access purposes. The Archival Master File is never altered directly after it has been deposited in the archive repository (libArchive) other than modifying metadata or applying processes necessary to ensure its continuous usability over time.

Steps for Creating the Archival Master File

• Acquire a Capture File. The Capture File should have been created according to the recommendations in "Creating Capture Files."

• Run through the following Quality Control checklist to ensure that the image in the Capture File is true to the appearance of the original material in color, tone, and sharpness. It should still including any flaws and blemishes visible in the original material.

  • Ensure that the correct file format was used to save the file.
  • Check conformity and integrity of the file
    Use JHOVE (http://hul.harvard.edu/jhove/index.html)
  • Magnify the image to 100%
  • Do not bother to center the image or further deskew (straighten) the image.
  • Check the image to ensure that
    • the entire original object was captured
    • all significant details are visible
    • all text is legible.
  • Check the file name to ensure that
    • it has no non-standard characters in it
    • follows all local rules for file naming
  • the file attributes follow guidelines
    • resolution
    • file dimensions (Image > Image Size).
      • Ensure that the number of pixels on the longest side of the image is at least 3000 (oversize materials and slides have other requirements).
    • bit-depth (pixel depth) (usually 24-bit color, or 8-bit grayscale)
    • color space: Apple RGB 1998 or grayscale
  • Check the size of the image (Image > Image Size).
    • Ensure that the Document Size (print size) is the same as the original material scanned.
    • If any problems with the sizes are identified, rescan with settings adjusted accordingly.
    • Do not change any other setting in the Image Size menu.
• Check the metadata to ensure that
  • basic bibliographic metadata is present: Title is the most important.
  • IPTC headers have been populated: title/caption, department, keywords,
    • description: File > File Info > IPTC Contact, etc.]
  • Create a MD5 checksum and add to metadata
    (tools: http://hul.harvard.edu/ois/support/docs-drs.html#md5)
• If you want to create JPEG2000 versions, save the image (File > Save As JP2, lossy compression (9/7 irreversible/lossy), 100% quality, no tiles, RPCL order, 6 compression levels, precinct size no specified, region of interest not specified (or use a Batch process).

Resources

• Library Preservation at Harvard
  http://library.harvard.edu/preservation/digital-preservation (accessed October 1, 2013)
   
• Digital Curation Centre (DCC), providing a (UK) national focus on curation issues. (accessed October 1, 2013)
  DCC also publishes a Digital Curation blog "to discuss issues relating to the curation and long term preservation of digital science and research data."
   
• Digital Preservation Coalition
  http://www.dpconline.org/ (accessed October 1, 2013)
  UK services and portal, including links to Technology Watch reports (accessed October 1, 2013)
   
• NDIIPP, the U.S. National Digital Information Infrastructure and Preservation Program
  http://digitalpreservation.gov/ (accessed October 1, 2013)
   
• PADI, Preserving Access to Digital Information, a comprehensive and current subject gateway to international preservation resources
  http://www.nla.gov.au/padi/ (accessed October 1, 2013)