17.327 scanning specifications

From: Humanist Discussion Group (by way of Willard McCarty willard.mccarty@kcl.ac.uk)
Date: Thu Oct 23 2003 - 01:31:00 EDT

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                   Humanist Discussion Group, Vol. 17, No. 327.
           Centre for Computing in the Humanities, King's College London
                         Submit to: humanist@princeton.edu

       [1] From: Patricia Galloway <galloway@ischool.utexas.edu> (22)
             Subject: Re: 17.323 scanning specifications

       [2] From: { brad brace } <bbrace@eskimo.com> (21)
             Subject: Re: 17.323 scanning specifications

             Date: Thu, 23 Oct 2003 06:18:06 +0100
             From: Patricia Galloway <galloway@ischool.utexas.edu>
             Subject: Re: 17.323 scanning specifications

    In the mid-1990s the resolution for affordable scanning was not great. Plus
    the notion that the original photograph and/or its negative will always
    stay viewable in the required detail is a misconception, no matter how
    carefully they are preserved. The cost-benefit of imaging for preservation
    can easily be represented graphically: X-axis time, Y-axis quality. First
    guarantee that both the original and the image of it are preserved
    optimally, which in the latter case means without loss of information but
    in the former case cannot. Determine the difference in quality between the
    image and the original. Draw a horizontal line to make a temporal graph of
    the unchanging image quality. Then represent the (better) quality of the
    original somewhere to the north of that of the image to begin with, but
    draw the curve charting its inevitable deliquescence over time (there is a
    huge literature on this). For any time after the two curves intersect, you
    have justified the imaging and the maintenance of the image, because the
    image will now be better than the original and past this point the original
    will get worse and worse. The main trouble with imaging projects is that
    they are frequently targeted at short-term goals and often have little
    serious commitment (or institutional capacity to make such a commitment) to
    the preservation of the image unchanged in quality and still viewable over
    the long term, long enough for the curves to cross.
    Pat Galloway
    University of Texas at Austin

             Date: Thu, 23 Oct 2003 06:18:50 +0100
             From: { brad brace } <bbrace@eskimo.com>
             Subject: Re: 17.323 scanning specifications

    > From: François
    > Your very specific question raises a more general one regarding the
    > _purpose_ of an image archive. It reminded me of a lecture given by
    > Prof Manfred Thaller at Queen Mary (University of London) some time ago,
    > in the mid 1990's. In it, he showed us two slides, apparently identical,
    > of a victim of the holocaust. He then said that one was a contemporary
    > photograph (yes, the Nazis actually photographed people before murdering
    > them!) and the other was a digitized image of it. He went on to say that
    > if you wanted to know what the person looked like, either image would
    > do. However, with the original, he could zoom in on to a button of the
    > uniform and see the manufacturer's name stamped on it, while the detail
    > was completely lost in the second image. If you needed the picture as
    > evidence for a prosecution of the uniform manufacturer on war crime
    > charges, only the original would do. An extreme example...
    > François Crompton-Roberts

    The curious thing is that a very high-resolution digitalized
    image can extract _more detail than the "original." If they
    haven't already, digital images, may soon eclipse analogue
    versions, as being superior and "culturally-credible."

    { brad brace } <<<<< bbrace@eskimo.com >>>> ~finger for pgp

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