Ну как-то так.
forceSmoothing (MovieClip.forceSmoothing property)
public forceSmoothing : Boolean
A Boolean value that determines whether images that are added through the loadMovie() method and are in the same hierarchy level as the movie clip are smoothed when scaled. Setting forceSmoothing to true decreases rendering performance. The default value is false.
Код AS1/AS2:
my_clip.forceSmoothing = true
Но я бы не сказал, что толку много.