This is a plugin similar to chromakey.
Camera on the tripod. Aim at blue screen. Set
exposure, white balance, etc. Then walk on the
blue screen and do stuff.
A frozen frame of the initial empty blue screen
will be used to flipon the alpha chanel.
Can actually be used with non-uniform and
multiple color backgrounds. I.e. As long as
the camera is on a tripod and the background
doesn't change, then each pixel is keyed
agains the the appropriate color of the initial
frame and changed to alpha if it is sufficiently
close. Tolerances are adjustable.
Speed is faster than chromakey because
there is no floating point in the renderpath...
comparisons are done in YUV space.