Operation Manual

Chapter 8: Two-track editing with Studio Plus 163
saturation and intensity – that in combination with hue
make a complete color specification. The chosen hue is
shown by the position of the highlighted region on the
circumference of the color circle display.
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.
Color tolerance: This slider controls the width of the
range of hues that will be recognized as belonging to
the “key color”. Moving the slider to the right increases
the angle of the arc covered by the highlighted region
on the color circle.
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.