Apple Keynote '09 - Manual (Page 78)

To learn more about reducing the size of movie files, see “Reducing the Size of Media
Files” on page 111.
Note: After you’ve reduced the size of masked or shrunk image files, you won’t be able
to restore them to their original size. If you later want to restore their original size, you
must add the original image files to the document again.
Images used in image fills or with action builds cannot be reduced in this way. Some
types of image files also may not be reducible.
Removing the Background or Unwanted Elements from an Image
The Instant Alpha tool enables you to make parts of an image transparent in order to
remove the image background.
You’ll get the best results removing solid colors with clear boundaries around them. To
remove areas that are less distinct, select a smaller area and repeat the process.
To remove unwanted elements:
1 Select the image.
2 Click Alpha in the toolbar (or choose Format > Instant Alpha).
3 Click the color you want to make transparent, and then drag slowly over it.
Dragging selects the contiguous
area that uses colors similar to
the color you click.
As you drag, the selection grows to include the contiguous area that uses similar
colors. You can control how much of the image is selected by dragging less or more.
If you hold down the Option key while you drag, all instances of the color that you’re
dragging over will be removed from the image.
78 Chapter 5 Working with Images, Shapes, and Other Objects