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Apparatus for detecting relative crowding in a hall

  • US 4,924,416 A
  • Filed: 09/09/1988
  • Issued: 05/08/1990
  • Est. Priority Date: 10/02/1987
  • Status: Expired due to Term
First Claim
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1. An apparatus for determining relative crowding by people of a hall comprising:

  • a variable intensity illuminator for varying illumination intensity in a hall;

    a television camera for generating images of the hall, the images having a brightness depending upon the illumination intensity in and crowding of the hall and being composed of pixels;

    means for storing the images generated by said camera as;

    (a) current video data;

    (b) reference video data obtained with a predetermined illumination intensity and a predetermined degree of crowding in the hall; and

    (c) old video data, periodically replaced with current video data; and

    a computer receiving the current, reference, and old video data from said means for storing for;

    (i) comparing the brightness of the current video data to the brightness of the reference video data;

    (ii) comparing the brightness of the current video data to the brightness of the old video data; and

    (iii) replacing the old video data in said means for storing with current video data in response to the comparison of the brightness of the current video data to the brightness of brightness produced with a reference illumination intensity; and

    a computer operatively connected to said illuminator controller for calculating relative crowding in the hall from the illumination intensity producing the image of the hall of predetermined brightness relative to the reference illumination intensity.

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