Controlling Miniaturization in Stereoscopic 3D Imagery

Viewers of stereoscopic three-dimensional (3D) imagery can perceive the absolute size of objects within a scene. On larger screens, the perceptual size of objects commonly appears bigger than reality, which matches viewers’ expectations for big-screen, larger-than-life theatrical experiences. In contrast, the geometry involved in stereoscopic imaging can cause the perceptual size of objects to appear smaller than reality (miniaturization). Miniaturization can be distracting for viewers and is more extreme on smaller screens like 3D television and handheld 3D devices. A common misconception is that miniaturization occurs only when the stereo camera separation (interaxial) is larger than the human eye separation (interocular), or larger than 2.5 in. In this paper, counter examples of this misconception are provided, as well as an analytical framework that allows stereo camera operators to accurately predict what the miniaturization effect will be on any screen size. Example stereoscopic 3D images are shown to illustrate control of perceptual size.