Adobe 23101335 User Guide - Page 209

Storing masks in alpha channels, About alpha channels Photoshop

Page 209 highlights

ADOBE PHOTOSHOP 6.0 199 User Guide • Selected Areas to have masked or protected areas appear white (transparent) and to have selected areas appear black (opaque). Painting with white increases the masked, protected area; painting with black increases the selected area. With this option, the Quick Mask button in the toolbox appears as a gray circle on a white background ( ). To toggle between the Masked Areas and Selected Areas options for quick masks, Alt-click (Windows) or Option-click (Mac OS) the Quick Mask mode button. 3 To choose a new mask color, click the color box, and choose a new color. For more information, see "Using the Adobe Color Picker" in online Help. 4 To change the opacity, enter a value between 0% and 100%. Both the color and opacity settings affect only the appearance of the mask and have no effect on how underlying areas are protected. Changing these settings may make the mask more easily visible against the colors in the image. 5 Click OK. You can convert this temporary mask to a permanent alpha channel by switching to standard mode and choosing Select > Save Selection. Storing masks in alpha channels In addition to the temporary masks of Quick Mask mode, you can create more permanent masks by storing them in alpha channels. This allows you to use the masks again in the same image or in a different image. You can create an alpha channel in Photoshop and then add a mask to it. You can also save an existing selection in a Photoshop or ImageReady image as an alpha channel that will appear in the Channels palette in Photoshop. About alpha channels (Photoshop) An alpha channel has these properties: • Each image (except 16-bit images) can contain up to 24 channels, including all color and alpha channels. • All channels are 8-bit grayscale images, capable of displaying 256 levels of gray. • You can specify a name, color, mask option, and opacity for each channel. (The opacity affects the preview of the channel, not the image.) • All new channels have the same dimensions and number of pixels as the original image. • You can edit the mask in an alpha channel using the painting and editing tools.

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199
ADOBE PHOTOSHOP 6.0
User Guide
Selected Areas to have masked or protected areas
appear white (transparent) and to have selected
areas appear black (opaque). Painting with white
increases the masked, protected area; painting
with black increases the selected area.
With this option, the Quick Mask button in the
toolbox appears as a gray circle on a white
background (
).
To toggle between the Masked Areas and
Selected Areas options for quick masks, Alt-click
(Windows) or Option-click (Mac OS) the Quick
Mask mode button.
3
To choose a new mask color, click the color box,
and choose a new color.
For more information, see “Using the
Adobe Color Picker” in online Help.
4
To change the opacity, enter a value between 0%
and 100%.
Both the color and opacity settings affect only the
appearance of the mask and have no effect on how
underlying areas are protected. Changing these
settings may make the mask more easily visible
against the colors in the image.
5
Click OK.
You can convert this temporary mask to a
permanent alpha channel by switching to standard
mode and choosing Select > Save Selection.
Storing masks in alpha channels
In addition to the temporary masks of Quick Mask
mode, you can create more permanent masks by
storing them in
alpha
channels
. This allows you to
use the masks again in the same image or in a
different image.
You can create an alpha channel in Photoshop and
then add a mask to it. You can also save an existing
selection in a Photoshop or ImageReady image as
an alpha channel that will appear in the Channels
palette in Photoshop.
About alpha channels (Photoshop)
An alpha channel has these properties:
Each image (except 16-bit images) can contain
up to 24 channels, including all color and alpha
channels.
All channels are 8-bit grayscale images, capable
of displaying 256 levels of gray.
You can specify a name, color, mask option,
and opacity for each channel. (The opacity affects
the preview of the channel, not the image.)
All new channels have the same dimensions and
number of pixels as the original image.
You can edit the mask in an alpha channel using
the painting and editing tools.