Under certain circumstances, conventional stereoscopic imagery is subject to being misinterpreted. Stereo
perception created from two static horizontally separated views can create a "cut out" 2D appearance for objects
at various planes of depth. The subject volume looks three-dimensional, but the objects themselves appear flat.
This is especially true if the images are captured using small disparities.
One potential explanation for this effect is that, although three-dimensional perception comes primarily from
binocular vision, a human's gaze (the direction and orientation of a person's eyes with respect to their
environment) and head motion also contribute additional sub-process information. The absence of this
information may be the reason that certain stereoscopic imagery appears "odd" and unrealistic. Another
contributing factor may be the absence of vertical disparity information in a traditional stereoscopy display.
Recently, Parallax Scanning technologies have been introduced, which provide (1) a scanning methodology,
(2) incorporate vertical disparity, and (3) produce stereo images with substantially smaller disparities than the
human interocular distances.1 To test whether these three features would improve the realism and reduce the
cardboard cutout effect of stereo images, we have applied Parallax Scanning (PS) technologies to commercial
stereoscopic digital cinema productions and have tested the results with a panel of stereo experts.
These informal experiments show that the addition of PS information into the left and right image capture
improves the overall perception of three-dimensionality for most viewers. Parallax scanning significantly
increases the set of tools available for 3D storytelling while at the same time presenting imagery that is easy and
pleasant to view.