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. 07, 1990
Filed:
Mar. 20, 1989
Michael Hausdorfer, Muhltal, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A decision signal for switching or fading between foreground and background television signals in accordance with the chroma-key method is subjected to vertical scan delay filtering for line signal averaging in television signals to avoid disturbance of the decision signal by results of the field interlace feature of a standard television signal. The delay for such filtering is provided by a random access digital memory and provides a delay of one period of the vertical scan frequency. Filtering is obtained by averaging delayed and undelayed output of the chromakey color selection signal or by recursively filtering that signal utilizing the same period and type of delay.