A client recently gave me 2 bmp sequences - a 600 frame RGB image sequence along with an alpha matte of the same. He wants me to replace the background, which would be no problem in After Effects or Nuke, but he wants it done in Photoshop CS6.
I tried importing both sequences as layer stacks and played around with blending modes and nested layer groups, but so far, no luck. I could either affect the subject, or the BG, but never both.
Since I can't manually layer mask 600 frames, is it possible to get this done in scripting? Just mask each RGB frame using it's respective alpha matte. I have experience with photoshop automation, but I haven't touched scripting, apart from using the default scripts.