The basics of Alpha

AlphaToys is a set of plug-ins that use transparency.
This page will give you a quick introduction to the basics behind transparency.

Channels

RGB images are made up of three different color components; red (R), green (G) and blue (B).
These color components can all have different values; a low value represents less of that color component, a high value means more.
To represent these color components, graphics applications use a single grayscale image for each individual color component in an image; a dark shade of gray means less of the color component the channel represents, a bright shade means more.
These grayscale images are called "channels", so an RGB image has a red channel, a green channel and a blue channel.
To store transparency, graphics applications add another one of these "channels", called the alpha channel.

The Alpha channel

The alpha channel is just another grayscale image.
In the alpha channel, a dark shade of gray means the corresponding pixel is more transparent, a brighter shade is less transparent.
Since the alpha channel is just another grayscale channel, you can change it just like you can with the R, G and B channels of an RGB image.

Why AlphaToys

Most graphics applications, however, won't let you do this.
This is where AlphaToys comes in.
AlphaToys gives you a number of standard filters common to all graphics applications, but apply these effects to the alpha channel.
One of the main benefits of being able to use alpha channels, is that it makes it possible to do a lot of typical effects using separate layers or even Smart Objects.
Using separate layers or Smart Objects mean you can still go back to the original layer and tweak settings without having to retrace and redo all other steps.
AlphaToys also work with scripting and actions, which means you can automate a lot more of your workflow than you could with just the graphics application.

Some terminology

When working with AlphaToys or the alpha channel in general, you'll come across some words you may or may not know.
Even when you DO know these words, it's a good idea to define them here, so you know what AlphaToys means by them.

Transparency

This is the general term used to describe how much of the background or underlying layers you can see through an image.

Transparent

When using the term "transparent", we mean any part of the image where you can see through (part of) an image; no pixels of the transparent part can be seen.

Opaque

This is the exact opposite of transparent; you cannot see through an opaque image, if blocks from view all background and underlying layers.

Semi transparency

When talking about "semi transparency", it means any pixel which is neither fully transparent nor fully opaque.

AlphaToys v1.0 manual - Copyright © 2009 VanDerLee. All rights reserved.