View Full Version : What is an alpha channel?

05 May 2003, 10:42 PM
I've seen a lot of use of the alpha channel, most of the time never reproducible myself ... so my question is... what is an "alpha channel?" And what exactly does it do?

05 May 2003, 01:46 AM
Check this out for starters:

Depending on what type of application you're using the alpha channel in, it can serve a couple purposes. But it has one specific characteristic in any case -- it contains only 256 levels of grey tones, including black and white.

In 3D for instance, it can serves and a masking tool.
In Photoshop, an alpha channel can store a selection, be used for a layer mask, or create a heightmap 'bump' effect when applied through the 'Lighting Effects Filter'.

Do a search on the term.
You'll find tons of specific info on this topic. :bounce:

05 May 2003, 05:11 AM
oooh, very cool, thanks for the nfo.

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