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:
Apr. 13, 1993
Filed:
Sep. 10, 1991
David F Fellinger, Westlake Village, CA (US);
Ultimatte Corporation, Chatsworth, CA (US);
Abstract
An apparatus and method which control the gain of the key signal dynamically and thereby compensate for the effects of an unevenly lit backing or lens vignetting. This dynamic control occurs over a video frame and has the effect of modulating the key signal. In this connection, there are four possible gain controls as follows: a) a horizontal ramp to increase the level of either side (left or right) of the key signal; b) a vertical ramp to increase the level of the top or bottom of the key signal; c) a horizontal parabola to raise or lower the gain of both sides of the key signal simultaneously to nullify lens effects; and d) a vertical parabola to raise or lower the gain of both the top and bottom of the key signal simultaneously to nullify lens effects.