University of illinois Urbana-Champaign

Image of the Week Gallery

Green-Screen Compositing Test for Psychology Stimulus

Download original media

Media Details

Created 10/15/2002

In an attempt to ascertain whether infants understand gravity, they are shown two video clips. The first shows a cylinder gliding across a table. The second shows the same cylinder in the same motion, but with half the table missing. Infants who understand gravity will be surprised and respond with prolonged looking at the scene. The image was produced using green-screen compositing techniques in Final Cut Pro. The image at top-left is a still from the first clip; middle-left shows the green-screen clip; bottom-left shows the blank scene. The contents of the second clip's green color are subtracted to show the blank scene through. The image at right is a still from the final composite.


  • Yuyan Lao , Dept. of Psychology
  • Ben Grosser , ITG, Beckman Institute
Back to all images