I'm hoping someone can give me a hint on this one. I've been creating b/w mattes in Elastic Reality. I'd like to take that matte (preferably as an avi format rather than a sequence of clips) and make it into the alpha channel for a differnt avi. (Note- these clips contain a fair amount of movement- they aren't simply static.)

In short- I want to turn the b/w matte I've created based on a short clip into the alpha channel for that clip. I need the alph channel because I want to apply both transparency and an alpha glow. I really need to 'give' the clip the b/w matte as its alpha channel.

Any ideas- I've got Premiere pro- but was hunting around in avisynth, as that seemed the most likely option for this kind of manipulation. Still not having any luck with it. Anyone have any ideas?