Often you create an image with an alpha channel in Photoshop, import it to Viz Artist/Engine and only then realize that your alpha channel is inverted. Or you find an image in the Viz Artist/Engine pool that you want to use, but the way you want to use it is where the RGB is actually the alpha channel.
pxInvert allows you to perform these operations without adding yet another image to your image pool, or overloading your scenes with a few versions of the same image, where the difference is simple flips of the channels.
This plug-in allows you to invert each of the color channels RGB and Alpha individually, and to use the RGB as alpha and the alpha as RGB.
Note: This plug-in is located in: Built Ins -> Shader -> PixelFX