Composite Channels

A reader was a bit confused by my response to a channel question, in which I referred to an image in RGB mode as having 4 channels.

There are, of course, the Red-Green-Blue channels as shown above. There is also a composite channel (RGB) which is used to display the image. The composite counts as a channel as well.

LAB has four total channels, CMYK has five, and Grayscale has but one.

Enjoy.