Apple iWork '08 - Manual (Page 52)

52 Chapter 1 Getting Started with Pages
Removing Unwanted Areas from an Image
The Instant Alpha tool converts areas of a certain color to transparent. This tool is
useful, for example, for removing an unwanted background.
To remove the background from an image:
1 Select the image.
2 Choose Format > Instant Alpha.
3 Drag slowly over an area you want to remove.
Dragging with the Instant Alpha
tool selects the contiguous area
that uses the same color.