XMult is a freeware plug in for Adobe After Effects.
XMult creates an alpha channel based on the highest luminance value of each pixel. A compensation is made to the RGB channels due to the attenuation of the applied alpha channel.
This is very useful for extracting a forground object filmed against a black background, e.g. explosions or fireworks
XMult supports 8, 16 & 32bpc
After Effects 6.0 or later
Windows XP, Windows Vista & Windows 7
MacOS 9.2 and natively on MacOSX. (PPC, Intel & Intel x64)
Current version is v1.0.0