Using the luma key graph – Matrox Electronic Systems Matrox RT.X2 User Manual
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Chapter 4, Setting Up Realtime Effects with Adobe Premiere Pro
control as defining a “Transparent to Opaque” range for keying the dark areas
of your foreground image.
•
High Clip
This control is similar to
Low Clip
, except you use it to select
the higher (brighter) luminance values to be keyed.
•
High Gain
This control is similar to
Low Gain
, except you use it to set the
range of luminance values you want to be partially transparent based on the
value set by the
High Clip
control. You can think of the
High Gain
control
as defining an “Opaque to Transparent” range for keying the lighter areas of
your foreground image.
¦
Note
The values you can select using the
Low Clip
and
Low Gain
controls
are dependent on the
High Clip
and
High Gain
controls, and vice versa. This
prevents the low and high controls from keying on the same luminance values.
•
Mask
Allows you to apply a mask to your effect. For more information,
“Applying a mask to your effect”
.
•
Transparent Outside Mask
Select this option to apply transparency
outside the mask area. This allows you to define a mask area where you want
the keying to be performed, and show only your underlying image outside
the mask. For more information, see
“Applying a mask to your effect”
.
• Invert Key
Select this to invert the key selection, giving you the opposite
result of what you originally selected
•
Show Key as Output
Select this to display the matte used to create your
key effect. This enables you to further refine your key settings. For example,
when you display the matte, areas of your clip that are completely
transparent appear as black, and opaque areas appear as white. If you notice
some white spots that you want to key, you can adjust the key controls until
the undesired white spots disappear.
Using the luma key graph
The luma key graph contains a luminance spectrum and a luminance eyedropper.
You can drag the handles in the luminance spectrum to adjust the
Transparency
,
Low Clip
,
High Clip
,
Low Gain
,
and
High Gain
properties.
Eyedropper