Photoshop CS3 Photo Effects Cookbook

Glossary

Adjustment layer

A specialized layer that can be handled as a conventional layer, but designed to enact effects on layers below it in the image "stack." These include changes to levels, contrast, and color, plus gradients and other effects. These changes do not permanently affect the pixels underneath, so by masking or removing the adjustment layer, you can easily remove the effect from part or all of an image with great ease. You can also return and change the parameters of an adjustment layer at a later stage.

Alpha channel

A specific channel used to store transparency information. Alpha channels can be used to store and control selections and masks.

Blending mode

In Photoshop, individual layers can be blended with those underneath, rather than simply overlaying them at full opacity. Blending modes control the ways in which the layers interact, enacting changes on one layer using the color information in the other. The result is a new color based on the original color and the nature of the blend.

Burn

A method of locally darkening areas in a photograph. The opposite of Dodge.

Channels

In Photoshop, a color image is usually composed of three or four separate single-color images, called channels. In standard RGB mode, the Red, Green, and Blue channels will each contain a monochromatic image representing the parts of the image that contain that color. In a CMYK image, the channels will be Cyan, Magenta, Yellow, and Black. Individual channels can be manipulated ...