Using a Channel to Make a Selection
Photoshop CS3 Tutorial
How to Make a Selection with a Channel in Photoshop
Selections can be made in Photoshop using a variety of tools. If you think you may need the selection in the future, it is worth saving.
Selections can be saved as paths, channels and layer masks. One advantage to channels over paths is that the selection is saved as a grayscale image where the white areas are selected and the black sections are not. The gray areas select the image with varying degrees of transparency.
Open an image in Photoshop (File > Open).
Use one of the lasso tools to make a selection.
In the Channels palette click the Save Selection as Channel icon.
Double-click the channel name and rename the channel. Click the channel marked RGB to return to the image.
Returning to the Layers palette, deselect the image (Cmd/d (PC-Ctrl/d)).
To make your saved selection, choose Select > Load Selection.
Select your new channel from the Channel pull-down menu. Click the Invert box and click OK. Double-click the layer icon and press the Delete key to remove the non-object pixels.
Pen Tool Selections
For complex selections you may want to make your selection with the Pen tool. For more information, see topic Selecting With the Pen Tool.