5
Turn on the Preview option to check the filter effect. When the
settings are correct, click OK.
To save a custom filter: In the Custom dialog box, enter the fil-
ter settings and click Save. Enter a name and location for the filter
and click Save.
To load a custom filter: In the Custom dialog box, click Load.
In the directory dialog box, select the filter file and click Open.
Combining image channels
The Calculate Image command lets you combine channels to create
selection masks for effects like embossing text in an image. By add-
ing, subtracting, and multiplying channels, you can also enhance
shadows and highlights. The Calculate Image command combines
corresponding pixels from two channels by the method you choose.
You can place the result in a new or existing channel.
To combine channels
1
With an image in edit mode, choose Image > Calculate.
2
Choose the first channel in the Source 1 menu. If you want to
invert the channel, select Invert. For more information, see Invert-
ing colors in images on page 34.687.
3
In the Source 2 menu, choose the channel you want to combine
with the Source 1 channel. If you want to invert the channel, select
Invert.
4
In the Blending area, choose an option in the Use menu. See
Descriptions of Calculate blending options, page 35.725
5
Enter an opacity from 0 to 100 percent for Source 1. Other
options are available for some Blending methods.
6
If you want to mask Source 1, select Mask in the Blending area
and choose a channel in the menu. To invert the mask, select Invert
in the Blending area.
7
Choose the name of a destination channel or choose New in the
Result menu. If you select an existing channel, Canvas replaces the
channel with the results of the Calculate Image operation.
8
Click OK to calculate the channel using the current settings.