Image matte key effect, Luma key effect – Adobe Premiere Pro CS4 User Manual
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USING ADOBE PREMIERE PRO CS4
Effects and transitions
Last updated 11/6/2011
Eight-Point, Four-Point, and Sixteen-Point Garbage Matte effects
(32-bit) The three Garbage Matte effects aid in cropping out extraneous portions of a shot so that you can apply and
adjust a key effect more effectively. The mattes are applied with either four, eight, or 16 adjustment points for more
detailed keying. Once you apply the effect, click the Transform icon
next to the effect name in the Effect Controls
panel. This displays the garbage matte handles in the Program Monitor. To adjust the matte, drag the handles in the
Program Monitor or drag the controls in the Effect Controls panel.
More Help topics
Mask out objects with garbage mattes
Image Matte Key effect
The Image Matte Key effect keys out areas of a clip’s image based on the luminance values of a still image clip, which
serves as a matte. The transparent areas reveal the image produced by clips in lower tracks. You can specify any still
image clip in the project to serve as the matte; it does not have to be in the sequence. To use a moving image as the
matte, use the Track Matte Key effect instead.
More Help topics
Define transparent areas with Image Matte Key
Luma Key effect
(32-bit) The Luma Key effect keys out all the regions of a layer with a specified luminance or brightness.
Use this effect if the object from which you want to create a matte has a greatly different luminance value than its
background. For example, if you want to create a matte for musical notes on a white background, you can key out the
brighter values; the dark musical notes become the only opaque areas.
White background of original (top and left) is removed using the Luma Key effect and composited over underlying layer (right).
Adjust the following settings as necessary:
Threshold
Specifies the range of darker values that are transparent. Higher values increase the range of transparency.
Cutoff
Sets the opacity of nontransparent areas specified by the Threshold slider. Higher values increase transparency.
You can also use the Luma Key effect to key out light areas by setting Threshold to a low value and Cutoff to a high
value.