×

Video signal coding by video signal polarity reversal on the basis of brightness level comparison

  • US 4,340,906 A
  • Filed: 05/14/1980
  • Issued: 07/20/1982
  • Est. Priority Date: 05/14/1980
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of coding video signals by repetitive alteration of the coding mode including the steps of:

  • (a) detecting a change in the picture scene carried by the video signal by comparing the brightness level of a predetermined time period of the video signal which time period includes a video signal field with the brightness level of the video signal over the succeeding predetermined time period, the brightness level being determined by comparing the instantaneous brightness level at successive subdivisions of said time period, each less than a single horizontal line, with an average brightness level,(b) altering the coding mode of the video signal if the difference in brightness level between successive predetermined time periods exceeds a given value,(c) and preventing such alteration of the coding mode except only between frames of the video signal.

View all claims
  • 13 Assignments
Timeline View
Assignment View
    ×
    ×