"plug-in-gap-range-flatten"

Flatten Frames

    Start from Menu:
      <Image>/Video/Frames Flatten

    This feature flattens all the frames in the range
    specified via "From Frame" and "To Frames".

    Warning:    
    Flattening melts down all layers to one resulting
    background layer and replaces transparent regions
    with the background color.
    (because flattening removes the alpha cahnnel)
    this is done in all handled frames.