14.1 Selection Masks
Figure 14-1 shows a photograph where we made a selection with the Select by Color tool (). In the tool options, we increased the Threshold value to 20.0 to select the entire sky. Then we applied Image: Select > Save to Channel.
The Channels Dialog
Figure 14-2 shows the Channels dialog, which is a dockable dialog initially located in the multi-dialog window. The first three rows correspond to the image’s Red, Green, and Blue channels. These channels are grayscale images; each of their pixel values corresponds to the value of that color component in the image itself. That’s why the thumbnail appears as a grayscale image. Click and ...