Trans Blacks or Trans Whites

Hi Guys,

If I have a movie with a black background, is it possible to make this black background transparent with a visual FX?
The same question for a white Background.

I haven't found a way yet,
but that would be a great feature i think.


Greetings,
Tim

I found an easy way to do that without Alpha channel in the media.
You need to use the luma mode for the layer who you need to remove black and move the dimmer to select the good Luma. The problem is, with this mode you don't have dimmer and the sides are not so smooth...
Maybe there is a better to do that.



++, Seb.

The pro way to do it is to use an alpha channel in the media file.  The alpha channel contains the transparency info, so when the alpha channel is white the media will be visible, and when the alpha channel is black the media will be transparent.  Using this method, the black areas inside your logo can be opaque whilst the black areas around the outside of the logo can be transparent.  You can also get a nice smooth edge around the logo because the alpha channel supports 256 levels of opacity between black and white, which allows you to have a smooth edge rather than a hard cut threshold like a luma key.  

In Ai the alpha channel blend mode supports this type of media.  The media can contain an alpha channel with these three media formats: AiM, PNG or TGA.