On 6/22/06, John Pye <[EMAIL PROTECTED]> wrote:
It's when you have 4 channels to describe each color: red, green, blue
and alpha. alpha is the opacity. If it's 1.0, then you color will show
up just as you expect. If it's zero you can see right through to
whatever's behind. Software that supports this needs to compose an image
for you by working out the combined color at each spot as the
combination of all the layers and their respective alpha values.
http://en.wikipedia.org/wiki/Alpha_channel
I understand now it. Thanks, John.
Paul
