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Automatic contrast correctin useful in video-to-print apparatus

  • US 5,291,313 A
  • Filed: 02/26/1993
  • Issued: 03/01/1994
  • Est. Priority Date: 02/27/1992
  • Status: Expired due to Term
First Claim
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1. An automatic contrast correction apparatus for correcting the contrast of a picture represented by color video signals, comprising:

  • an analog-to-digital converter for sequentially receiving said color video signals and converting said received signals into digital data;

    memory means for storing said digital data;

    amplification means comprising a plurality of amplifiers having different amplification factors switchably connected in parallel between said analog-to-digital converter and said memory means;

    extracting means for receiving said digital data supplied from said analog-to-digital converter and extracting data therefrom corresponding to a predetermined effective picture screen; and

    microcomputer means responsive to said extracted data and a predetermined reference value for calculating an average value of the color signal data supplied from said extraction means, comparing said average value with said predetermined reference value corresponding to an optimized contrast, and switchably connecting one of said plurality of amplifiers between said analog to digital converter and said memory means depending upon the compared result.

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