The first thing that we need to do to convert our colour image is to convert each colour channel to a layer.



Figure 2: The initial unmodified image.


To convert the red channel to a layer:

• Choose the layer palette, and click on the red channel. As per figure 3, only the red channel should have the eye icon next to it. If you do not see the layer palette, select Window -> Channels.
• Select Select -> All to select the whole canvas.
• Select Edit -> Copy.
• Click on the RGB channel. All the eye icons next to each channel should be visible.
• Click on the Layers tab to bring it forward.
• Click on the original layer (here called Background) to make it the active layer.
• Select Edit -> Paste.
• Rename the new layer to "Red" or something else appropriate.
• Click on the eye icon for the new layer to make it invisible. We don't want the new layer to change what is displayed in the channels.
• Click again on the original layer (here called Background) to make it the active layer.

Figure 3: Selecting the red channel.



Figure 4: Pasting the contents of the red channel into a new layer.


Follow the same steps for the green and blue channels. At the end of this, you should have something like what is shown in figure 5.



Figure 5: The three channels converted to layers.