The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 18, 1992
Filed:
Sep. 12, 1990
Klaus-Dieter Muller, Weiterstadt, DE;
Bernhard Kreling, Darmstadt, DE;
BTS Broadcast Television Systems GmbH, Darmstadt, DE;
Abstract
For deriving a keying signal for a video mixer from a video pattern signal which may be derived by reference to the presence of a selected color in one of the video signals to be mixed, the level-shift voltage added to the video signal for producing the clipped video pattern signal, instead of being constant, is derived from at least one amplitude envelope signal produced from the video signal in order to overcome effects of non-uniform lighting or shadow effects in the picture that contains a selected color. The clip voltage is about half of the amplitude envelope signal. Preferably, both positive and negative amplitude envelope signals are generated and the level-shift voltage is then the mean value of the voltages contemporaneously represented by the envelope signals. The envelope signals are stored for a picture field interval before being used to generate the level-shift voltage.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile