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Production ChromakeyersExpanding the live production potential
Ever since Hollywood special effects pioneer Petro Vlahos developed the color difference blue screen process for the Motion Picture Research Council in the 1950s in an attempt to come up with an improved travelling matte technique, modern chromakey systems have been fountains of visual magic for broadcasters. Although these days every sophisticated analog or digital switcher has its own chromakey capabilities built in, and most nonlinear editing systems can ?fix it in post with elaborate software plug-ins, the new advances in standalone real time chromakey systems that we will see at NAB2004 are expanding the live production potential behind this compositing wizardry.
The company Vlahos founded in 1976 to exploit his color substitution matte process, Ultimatte Corporation, has been the recognized leader in the field commonly referred to as chromakeying ever since and well be seeing their latest Ultimatte 10 and Ultimatte HD systems in Las Vegas. But Lynne Sauvé, President of Ultimatte, insists that todays Ultimatte process differs from traditional chromakeying. ?A chromakeyer is essentially an on/off switch, turning on either the foreground or the background, Sauvé explains. ?Ultimatte is really a matte-ing device that looks at the differences in the RGB values and creates a mask by subtracting their values to create truly linear transitions.
Essentially, Ultimatte processes the foreground and the background separately and composites the image elements by summing them rather than switching back and forth. This enables Ultimatte to create a fully additive mix so that a transparent or translucent object in the foreground can be added to the background scene in such a way that the background is still visible through it.
Ultimatte does make AdvantEdge software plug-ins for Adobe, Apple, Avid, and Discreet nonlinear editors for use in post. But Sauvé predicts that with the growing popularity of high definition Virtual Studio production techniques, which Ultimatte first demonstrated in conjunction with Sony at NAB 1990, live standalone blue- or green-screen compositing systems will increase in popularity.
?Since the Virtual Studio approach puts live actors in front of sets that have been previously created using computer graphics software, many overseas broadcasters are finding ways of overcoming space limitations dictated by high real estate prices, Sauvé says. ?Thats one reason we have brought out the new Ultimatte Insider board, a low-cost plug-in card that we OEM to switcher manufacturers to facilitate Virtual Studio applications. Ross Video and Echolab are the first to adopt Ultimatte Insider and the inclusion of this technology makes compositing quality with their switchers a non-issue for their customers worldwide.
In the mid-'90s, with the advent of digital technology, an engineer in Japan, Yaz Mishmia, came up with a concept for segmenting the R G B color space and developed a technology called Primatte that was originally marketed by Photron as a standalone chromakeyer for post on a Silicon Graphics platform. However, as Scott Gross, Product Manager for Primatte Products at Photron, U. S. A, Inc. discovered, it quickly became apparent that customers really wanted to use this technology as a plug in for high end graphics workstations such as Discreets inferno and flame. So Primatte changed its marketing strategy and now its compositing software can be seen incorporated into edit suites in most high end effects houses.
Related Keywords:chromakey, nonlinear editing, NAB2004, Ultimatte, matte, broadcasters, NAB, digital switcher, Primatte, compositing, blue screen