User Guide

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ADOBE AFTER EFFECTS 5.0
User Guide
The interpretation methods include:
Ask User Displays a dialog box containing interpretation options each time you import an
unlabeled alpha channel.
Guess Attempts to determine the type of alpha channel used in the image. If After Effects
cannot guess confidently, it beeps.
Ignore Disregards all transparency data in the file.
Straight (Unmatted) Interprets the alpha channel as straight alpha. If the application you
used to create the footage does not premultiply the alpha channel, select this option.
Premultiplied (Matted with Black) Interprets the alpha channel as premultiplied with black.
Premultiplied (Matted with White) Interprets the alpha channel as premultiplied with white.
To import a footage file containing an alpha channel:
1 Choose File > Import > File. Locate and select the file and click Open.
2 In the Interpret Footage dialog box, select an option for alpha channel type. If you select
Treat As Premultiplied (Matted with Color), you can click the eyedropper and select a color.
3 Click OK.
To set the alpha channel interpretation method for a file:
1 In the Project window, select a footage item that includes an alpha channel.
2 Choose File > Interpret Footage > Main.
3 In the Alpha section, select an interpretation method.
4 Select Inverted to switch the opaque and transparent areas of the image, and click OK.
To set the default alpha channel interpretation:
1 Choose Edit > Preferences > Import.
2 For Interpret Unlabeled Alpha As, select the interpretation methods you want used by
default, and click OK.
UG.book Page 73 Wednesday, February 21, 2001 12:05 PM