Operation Manual

Chapter 6: Two-track editing with Studio Plus 131
The color circle on the Chroma key tool highlights a
range of hues (around the circumference) and color
saturation values (along the radius). Any pixel in the
overlay frame whose hue and saturation fall within
the highlighted region will be treated as transparent.
Saturation minimum: Saturation is the amount of hue
in a color. A pixel with zero saturation (corresponding
to the center of the color circle) has no hue: it falls on
the “gray scale”, whose extremes are white and black.
Chroma key works most effectively when the
background is highly and uniformly saturated, allowing
a high setting of this slider. In the real world, vagaries
of lighting and apparatus often result in a background
that falls short of the ideal. Moving the slider left
allows a wider range of saturation values to be matched,
indicated by a highlighted region that extends farther
towards the center of the color circle.
Softness: This slider controls the density of the
underlying video. When it is positioned all the way to
the left, the main video is entirely black. As you move
the slider to the right, the main video approaches full
density.
Spill suppression: Adjusting this slider may help
suppress video noise or fringing along the edges of the
foreground object.
Enable chroma keying: This checkbox allows you to
turn the chroma key effect on and off.