Perceptual Effects When Scaling Screen Size of Stereo 3D Presentations

Stereo three-dimensional (3D) content that is shot for the cinema may go on to be displayed on a number of different types of display devices, from domestic televisions to mobile devices. Stereo 3D content is scaled appropriately for the display device, but this scaling process alters the stereo 3D properties of the scene. For instance, when scaling cinema screen content to be shown on a domestic television screen, disparities are reduced, and the perceived depth of objects in the scene are affected in a nonlinear way. This paper explores the case of displaying stereo 3D cinema content on screens of a different size, both larger and smaller. It then explores in more detail the issues of showing cinema content on a domestic television, which include nonlinear scaling of depth. Experiments presented here show that the effects of this depth distortion are mitigated by two-dimensional perspective cues within the 3D scene, thus limiting the perceived distortion. The effect can be further mitigated by introducing a positive planar shift (of around 1%), which also improves comfort by keeping the depth range in the center of the comfort zone, reducing the vergence-accommodation conflict.