Grass Valley NewsEdit XT v.5.5 - Manual (Page 288)

Appendix Video Effects
286 Digital News Production
Luma Key
Keying inserts part of one picture into another to create a composite picture.
The Luma Key effect uses the color brightness of an incoming source to specify
where to cut the hole in the background.
Chroma Key (NewsEdit XT only)
The Chroma Key effect detects color (rather than luminance) in a video image
and replaces it with a new background. You can use this effect to put a reporter
sitting in front of a green screen into a background of a mountain scene, making
it appear that the reporter is sitting in front of the mountain.
Option Range Description
Clip 0 to 100 Adjusts the luminance (brightness) level in the key signal above which the
foreground or key fill video becomes visible over the background video.
Gain 0 to 100 Adjusts the sharpness of the key edge.
Invert On or Off Lets you see the video below the clip level; used for keying from dark
graphics on a light background.
Option Range Description
Hue 0 to 359 Sets the color (tint) of the shadow.
Range 0 to 359 Sets the angle of discrimination applied to the chroma when generating
a chroma key; the larger this angle is, the wider the range of colors will
be which result in an opaque key being generated.
Threshold 0 to 125 Specifies the minimum threshold required to generate a chroma key.
Softness 0 to 100 Controls the gain of the chroma key; the larger the value, the greater the
softness.
Suppress 0 to 100 Specifies the angle of chroma suppression used to generate a chroma key.
Luma Suppress 0 to 100 Indicates the amount of suppression applied to the luma when generating
a chroma key.
Chroma Suppress 0 to 100 Indicates the amount of suppression applied to the chroma when
generating a chroma key.
Invert On or Off Causes a hole to be cut in the background where a normal key retains the
background, and vice versa; makes the white areas of the key signal
produce transparency, and the black areas produce opacity, the opposite
of a standard key.