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Television receiver having picture magnifying apparatus

  • US 4,528,585 A
  • Filed: 03/30/1983
  • Issued: 07/09/1985
  • Est. Priority Date: 03/30/1983
  • Status: Expired due to Term
First Claim
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1. In a television receiver including a source of analog video signals, an analog-to-digital converter for producing digital samples representative of said analog video signals, a digital signal processor for producing digital luminance and digital chrominance samples from said digital samples, and a converting means for developing image representative signals from said digital luminance and said digital chrominance samples to produce a raster-scanned image on a raster-scanned display device,apparatus modifying said digital luminance and said digital chrominance samples for magnifying a predetermined area of said image by a factor 2I, said predetermined image area including M image elements and N lines of said raster scan, wherein I, M and N are integers, comprising:

  • window generating means for locating said predetermined image area at selectable predetermined horizontal an vertical positions of said image and for locating said magnified image area in predetermined horizontal and vertical relationship to said predetermined image area;

    a user-actuated device coupled to said window generating means for selecting said selectable predetermined horizontal and vertical positions;

    a first digital memory to which said digital luminance and said digital chrominance samples are applied, said first digital memory having first addressable storage registers for storing a number MxN of said digital luminance samples corresponding to said predetermined image area, and having second addressable storage reqisters for storing a number no greater than (M×

    N)/2 of said digital chrominance samples corresponding to said predetermined image area;

    addressing means responsive to said window generating means for developing first addressing signals to address said first and second addressable storage registers to store ones of said digital luminance and said digital chrominance samples at times when lines of said raster scan correspond to said predetermined image area, and for developing second addressing signals to address said first and second addressable storage registers to produce said stored ones of said digital luminance and said digital chrominance samples at times of said lines other than times of said lines corresponding to said magnified image area;

    interpolating means to which said produced stored ones of said digital luminance and said digital chrominance samples are applied for developing 2I ×

    M image samples representing modified digital luminance and modified digital chrominance samples corresponding to one line of said raster scan of said magnified image area, said interpolating means including a second digital memory for storing said 2I ×

    M image samples developed during an interval between times of said lines during which said magnified image is produoed, and for producing said 2I ×

    M stored image samples at said times of said lines during which said magnified image is produced, said interpolating means repeating the sequence of developing, storing and producing 2I ×

    M image samples for each line corresponding to the 2I ×

    N lines of said magnified image area; and

    multiplexing means responsive to said window generating means for applying said modified digital luminance and said modified digital chrominance samples in place of the digital luminance and digital chrominance samples, respectively, corresponding to said magnified image area,whereby the image produced on said display device includes a magnified portion thereof in accordance with said position selected by said user-actuated device.

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