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:
Jan. 07, 1997
Filed:
Jun. 01, 1995
Fred Rosenbaum, Austin, TX (US);
Paul S Yosim, Superior, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Disclosed is a method and apparatus for combining first and second video signals to produce a composite video signal for display. First and second video sources generate first and second video signals. A chroma key circuit is included for comparing each pixel of the first video signal with a preselected color and generating logic signals indicating whether or not each pixel matches the preselected color. An input lock map stores each of the logic signals when field data is in a first state and provides the logic signals on an output line thereof when the field data is in a second state. A frame buffer selectively receives (1) a complement of the logic signals when the field data is in the first state and (2) the logic signals when the field data is in the second state. The frame buffer is operative to store the composite video signal which is comprised of (1) a plurality of selected pixels from the first video signal which have corresponding logic signals that indicate they do not match the preselected color and (2) a plurality of selected pixels from the second video signal which have corresponding logic signals that indicate they correspond to pixel locations of the first video signal which matched the preselected color.