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In this chapter
- Understanding Channels
- Keeping Track of Layers, Channels, and Masks
- Using Masks to Create Selections
- Alpha Channels: Where Masks Are Stored
The Importance
of Channels
Information about colors in an image is stored in channels. An RGB
image has four color channels: red, green, blue, and a composite chan-
nel of every color. A CMYK image has five color channels: cyan,
magenta, yellow, black, and a composite channel of every color. Each
channel is a grayscale image of brightness values for that color.
Like the dye layers in slide film, these channels blend together when the
image is viewed normally and the appropriate colors are applied. The
power of Photoshop and Photoshop Elements lies in the capability to
view and manipulate these channels separately or in combination with
more than one channel.