Now that we have extracted the channels into separate layers, we can work at using these layers to form the final image. This will be done by setting the opacity of each of the three layers such that they combine to make the final image that you want.

To start, you need to find the channel that gives you the best range of texture. In the case of the image used in this example, the blue was confined primarily to the ice, snow, and shed, while the red was primarily confined to the trees. The green channel gave good texture overall, so I started with that.



Figure 6: Choosing a channel to start with.


To select a channel to use as your base:

• Click on the eye icon to show the channel you wish to view, then unclick it and click the next eye icon.
• When you have decided on which channel to use as your base, if its not already the bottom channel in the list, drag it down so that it is.

If you like what you see, you can use just this channel as your final image, but it is good to at least experiment with the other two to see if there is a way you can improve the image. In my case, I felt there was not enough detail on the trees, so taking the red channel, I made it visible and changed its opacity to 50%. I chose the red channel because it added more brightness and texture to the trees, while making the ice not quite as bright.

To change a layer's opacity:

• Select the layer for the channel you wish to use to modify the image.
• Click on the triangle next to the opacity box in the layers palette and drag the slider that is revealed.

Figure 7: Adjusting the opacity of the red channel.


You can now try doing this with the blue channel. In my case, I elected to not use the blue channel, since it had detail primarily in the ice and snow, and I felt that this region needed no more brightness or detail.

You can play around in this way until you find the combination of layers that you feel works best.