Quick links to procedures on this page:

Editing channels

You can edit a channel by modifying the size, shape, or opacity of its protected area, which ultimately becomes the protected area of the selection. The changes that you make to the channel do not directly affect the image until you load it as a selection. For more information, see To load a selection from an alpha channel.

Because the alpha channel is a grayscale image, you edit the channel by applying only white (to remove protected areas), black (to add protected areas), and shades of gray (to create semi-protected areas); no colors are available.

You can apply changes by selecting a brush and painting the changes in the channel.

protected areas channel

In this example, the channel has a few stray areas that are unprotected (left). The stray areas were transformed into protected areas by applying black brushstroke (right).

In addition, you can apply effects, such as feathering to soften the transitions between light and dark areas. This introduces a bit of opacity to the channel.

feather channel

A channel before and after feathering

You can also invert a channel to convert a protected area into an unprotected area.

channel inversion

A channel before and after inversion

In addition, you can introduce interesting effects by filling a channel with a pattern, gradient, or weave. For more information, see Working with color fills.

To paint in a channel Back to Top

 

Adjust the Opacity slider on the property bar.
Type a value in the Size box, or adjust the slider.
To apply an effect to a channel Back to Top
To feather a channel Back to Top
To invert a channel Back to Top
To fill a channel with a pattern Back to Top
To fill a channel Back to Top

 

On the property bar, type a value in the Tolerance box, or adjust the slider.
On the property bar, type a value in the Feather box, or adjust the slider.
Enable the Anti-Alias button on the property bar. Anti-aliasing is desirable when Feather is zero or extremely low.

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The Paint Bucket tool applies a fill only to a visible channel. Make sure the channel’s eye icon is open before using the Paint Bucket tool.

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You can return to the default Paint Bucket tool settings by clicking the Reset Paint Bucket Tool button on the property bar.

 


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