Adobe 23101335 User Guide - Page 200

Mixing color channels (Photoshop), Use the Channel Mixer with the Monochrome

Page 200 highlights

190 CHAPTER 7 Using Channels and Masks When deleting a channel from a file with layers, regardless of the method you use, Photoshop prompts you first to flatten the visible layers and discard hidden layers (if any) before deleting the channel. 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 some alternative color spaces, such as YCbCr. • Swap or duplicate channels. To mix color channels: 1 In the Channels palette, select the composite color channel. 2 Choose Image > Adjust > 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 223). 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 channel of varying opacity to the output channel-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. 7 Click OK.

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CHAPTER 7
190
Using Channels and Masks
When deleting a channel from a file with layers,
regardless of the method you use, Photoshop
prompts you first to flatten the visible layers and
discard hidden layers (if any) before deleting the
channel. 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 some alternative
color spaces, such as YCbCr.
Swap or duplicate channels.
To mix color channels:
1
In the Channels palette, select the composite
color channel.
2
Choose Image > Adjust > 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 223).
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 channel of varying
opacity to the output channel—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.
7
Click OK.