Opacity

Sets the opacity of the foreground element.

Foreground Type

Specifies whether the foreground clip is premultiplied, the clip is not premultiplied, the clip is on a specific backing color (which you can set using the Backing Color sliders), or the clip’s backing color should be set automatically.

Backing Color

Set’s the foreground’s backing color.

Output Alpha

Specifies the Alpha channel to use when compositing the image

BG & FG Composites the image using both the foreground and background images’ alpha channels.

BG Only Composites the image using the background image’s alpha channel.

FG Only Composites the image using the foreground image’s alpha channel.