Using Help
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271
Adobe Photoshop Help
Using Channels and Masks
Using Help
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Contents
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271
•
Choose Delete Channel from the Channels palette menu.
•
Click the Trash button at the bottom of the palette. Then click Yes.
To delete a channel (ImageReady):
Choose Select > Delete Channel, and choose the channel from the submenu.
Note:
When deleting a channel from a file with layers, visible layers are flattened and
hidden layers are discarded. This is done because removing a color channel converts the
image to Multichannel mode, which does not support layers.
Mixing color channels (Photoshop)
The Channel Mixer command lets you modify a color channel using a mix of the current
color channels. With this command, you can do the following:
•
Make creative color adjustments not easily done with the other color adjustment tools.
•
Create high-quality grayscale images by choosing the percentage contribution from
each color channel.
•
Create high-quality sepia-tone or other tinted images.
•
Convert images to and from alternative color spaces, such as YCbCr, which is used in
digital video.
•
Swap or duplicate channels.
To mix color channels:
1
In the Channels palette, select the composite color channel.
2
Choose Image > Adjustments > Channel Mixer.
3
For Output Channel, choose the channel in which to blend one or more existing
(or
source
) channels. (See
“Restricting blending to channels (Photoshop)” on page 298
.)
4
Drag any source channel’s slider to the left to decrease the channel’s contribution to the
output channel or to the right to increase it, or enter a value between –200% and +200%
in the text box. Using a negative value inverts the source channel before adding it to the
output channel.
5
Drag the slider or enter a value for the Constant option. This option adds a black or
white channel of varying opacity—negative values act as a black channel, positive values
act as a white channel.
6
Select Monochrome to apply the same settings to all the output channels, creating a
color image that contains only gray values.
Use the Channel Mixer with the Monochrome option applied to control the amount of
detail and contrast in the images you plan to convert to grayscale.
If you select and then deselect the Monochrome option, you can modify the blend of each
channel separately, creating a handtinted appearance.
