Some say that image is everything. If that’s true, what about
preserving an image? Isn’t that important, too?
The National Library of Medicine recently gathered some 50 people
from around the nation who are involved in the long-term preservation
of videos and films for an all-day meeting on the latest developments
in that field. Topics included proper storage methods to prolong
the lifetime of audiovisual materials, paths to truly lossless digital
copying and storage methods (“truly lossless” means that
the media will never lose quality if decompressed and recompressed),
and what types of metadata (supplementary material useful for cataloging,
search and retrieval) to keep.
The meeting, “Getting to Disk-based Lossless Digital Video
Compression,” took place at NLM’s Bldg. 38. The library
has been heavily involved in preserving historic and contemporary
biomedical films and videos, and seeking pathways to digital repositories.
Attendees represented a number of East Coast video archives including
the Library of Congress, the National Archives and Records Administration,
the National Holocaust Museum, PBS, Folkstream/UNC, Rutgers, Yale,
NYU, Johns Hopkins and the University of Maryland.
And what does that title mean? Software developer and meeting organizer
Glenn Pearson of NLM’s Communications Engineering Branch explains
it this way: “Two compelling circumstances face videotape archives
today — traditional non-digital videotape has become obsolete,
and the cost of storing information on hard disk is plummeting, much
faster than tape. So archives need to plan two simultaneous transitions,
from analog to digital, and from tape to disk. But what disk format,
video compression scheme and metadata will be the right stepping-stone
to the future?”
The meeting kicked off with presentations by NLM staff, including
Pearson. Paul Theerman, head of images and archives in the History
of Medicine Division, outlined NLM’s and NIH’s collection
and preservation efforts. Walter Cybulski, of preservation and collection
management, reviewed the endemic problem of film and tape deterioration
and equipment obsolescence, particularly for analog video.
NLM’s head of preservation Margaret Byrnes and George Thoma,
chief of the Communications Engineering Branch, also moderated panels
and presentations.
The meeting featured the first public demonstration of real-time,
full-screen, mathematically lossless video compression and decompression
based on the Motion JPEG 2000 (MJ2) standard. This was demonstrated
by Justin Dávila of Media Matters, Inc., with its prototype
PC board, using a short clip of a dancer crashing through a “glass” window.
Another demonstration, by Carnegie Mellon researcher Alexander Hauptmann,
showed recent work in automatic extraction of metadata (structured
information) from video. Possible applications in institutionalized
patient management included automatically detecting behaviors from
surveillance video, with images altered slightly to prevent loss of
privacy.