Channel Selections
Images store color information in Color Information Channels.
Color Information Channels
When a new image is opened, Color Information Channels are automatically created. The number of color channels created is determined by the image’s color mode. Each color of an RGB image, for example, has a channel for each color (Red, Green, and Blue).
To preserve an image's Color Information Channels, save files in a format that supports the image’s color mode.
To open the Channel Selection dialog:
In Edit mode, select from the main menu Select | Channel Selection... or press Ctrl + Alt + L.
Channel Selection Dialog Interface
The Channel Selection dialog interface is divided between four distinct areas:
- Channel Type,
- Levels,
- Preview, and
- Button bar.
The Channel Type field set lists all channels in the image grouped by type:
- RGB (Red Blue, Green),
- CMYK (Cyan, Magenta, Yellow, Black),
- LAB (L for perceptual lightness, A and B for Red, Green, Blue and Yellow), and
- HSL (Hue, Saturation, Lightness).
The Levels group contains a three-tabbed slider and associated graph for displaying adjustments made to the selected channel type. An Invert check box is available for selecting the inverse polarity of the image.
The Preview pane displays the latest mask for the original image. Directly below the image are a zoom slider, a numeric input zoom field, a Full Screen icon, and a 1:1 icon for displaying the original image with its original dimensions.
The button bar resides at the bottom of the dialog and contains a Help button, the Save in selection basket button, the Set as selection button, the Set as mask button, and the Cancel button. See the table below for an explanation of the button functionality.
| Help |
|
Opens the Channel Selection help page. |
| Set as selection | Makes the edits in the Channel Selector the current selection in the Preview pane. | |
| Cancel | Closes the Channel Selection dialog without taking any action. |
To edit an image through Channel Selection:
- Select from the main menu, Select | Channel Selection..., or press Ctrl + Alt + L.
- In the Channel Selection dialog, enable a Channel Type.
- Make fine adjustments in the Levels group.
- Do one of the following:
- Click the Save in selection basket button,
- Click the Set as selection button,
- Click the Set as mask button, or
- Click the Cancel button.