ADOBE PREMIERE PRO 2.0
User Guide
365
9
Click the Composite Using menu and choose one of the following:
Matte Alpha
Composites the clips using the alpha channel values of the image matte you selected in step 7.
Matte Luma
Composites the clips using the luminance values of the image matte you selected in step 7.
10
(Optional) Select the Reverse option to swap the areas that are opaque and transparent.
11
(Optional) If you’re animating the Image Matte Key, move the current-time indicator either in the Effect
Controls panel or Timeline panel and change the Image Matte Key settings.
A new keyframe appears in the Effect Controls timeline when you change the settings. Repeat this step as needed.
You can also adjust the interpolation between keyframes by editing the keyframe graph.
See also
“About keyframes” on page 230
“About alpha channels and mattes” on page 354
“To edit keyframe graphs in the Effect Controls panel” on page 238
About the Difference Matte Key
The Difference Matte Key creates transparency by comparing a specified still image with a specified clip and then
eliminating areas in the clip that match those in the image. This key can be used to create special effects. Depending
on the clip, it’s possible to use Difference Matte Key to key out a static background and replace it with another still
or moving image.
You can create the matte by saving a frame from a clip that shows the static background before the moving object
enters the scene. For best results, neither the camera nor anything in the background should move.
The following Difference Matte Key settings are adjusted in the Effect Controls panel:
Similarity
Broadens or reduces the range of color that will be made transparent. Higher values increase the range.
Smoothing
Specifies the amount of anti-aliasing (softening) that Adobe Premiere Pro applies to the boundary
between transparent and opaque regions. Choose None to produce sharp edges, with no anti-aliasing. This option is
useful when you want to preserve sharp lines, such as those in titles. Choose Low or High to produce different
amounts of smoothing.
Drop Shadow
Adds a 50% gray, 50% opaque shadow offset 4 pixels down and to the right from the opaque areas of
the original clip image. This option works best with simple graphics such as titles.
Reverse
Inverts the values of the matte.
Mask Only
Displays only the clip’s alpha channel. Black represents transparent areas, white represents opaque areas,
and gray represents partially transparent areas.
Note:
The RGB Difference Key uses color to define transparency much as the Difference Matte Key uses a still image.
See also
“About keying” on page 355
“About alpha channels and mattes” on page 354
To replace a static background behind moving objects
1
Find a frame of your clip that consists only of the static background.