Grass Valley Karrera Video Production Center v.4.0 - Manual (Page 63)

KARRERA — User Manual 63
MEs and Keyers
resulting from incomplete suppression. While coring can improve some
keys, it can easily be over done. Coring thresholds much above black will
affect dark grays that are actually part of the foreground subject, making
the chroma key composite look unnatural.
Fringe is used to restore color to the gray portions of the foreground color
resulting from secondary suppression adjustments. This control is only
active when secondary suppression is on.
Shdw provides controls of shadows that fall on the backing. Shadow Clip and
Shadow Gain allow selecting the range of the luminance portion of the fore-
ground that produces a shadow. Shadow Density is an opacity control for the
shadow and adjusts how much shadow is added to the background.
Background Mattes
Background matte generators create colors and washes. These can be used,
for example, as the backgrounds for keys.
Background mattes cannot use the wipe pattern generators available to
keyer and wipe mattes, and cannot use Utility video as a wipe source.
Instead background mattes employ a simple dedicated wipe generator that
creates a single, straight line.
Background matte control is available from the Control Panel (Multi-Func-
tion area,
Matt button in the Home menu) and from the Keyer, Matte menu,
which provides additional background parameter controls.
1. Go to the Mattes menu by pressing Keyer , Mattes .
2. Touch the BKGD button.
3. If not already selected, touch the Base Color data pad of the desired
Background (1 or 2). Use the top three soft knobs to adjust Base Hue ,
Base Saturation , and Base Brightness of the base fill color ( Figure 26 ).