Propagation of Depth Information from Local Regions in 3-D Scenes

Abstract

The effects of regions with local linear perspective on judgments of the depth separation between two objects in a scene were investigated for scenes consisting of a ground plane, a quadrilateral region, and two poles separated in depth. The poles were either inside or outside the region. Two types of displays were used: motion-parallax dot displays, and a still photograph of a real scene on which computer-generated regions and objects were superimposed. Judged depth separations were greater for regions with greater linear perspective, both for objects inside and outside the region. In most cases, the effect of the region's shape was reduced for objects outside the region. Some systematic differences were found between the two types of displays. For example, adding a region with any shape increased judged depth in motion-parallax displays, but only high-perspective regions increased judged depth in real-scene displays. We conclude that depth information present in local regions affects perceived depth within the region, and that these effects propagate, to a lesser degree, outside the region.

The ground dominance effect in the perception of relative distance in 3-D scenes is mainly due to characteristics of the ground surface

“…Perceived distance on the ground surface was also found to be affected by wearing base-up prisms, which deviated the direction of light and thus changed the visual angle between an object and eye level (Ooi, B. Wu, & Z. J. He, 2001), and by having a local region providing perspective information (Sauer et al, 2002).…”

“…He, & Shimojo, 1995;cf. Sedgwick, 1986), and have examined how manipulating information on the ground surface could affect the perceived location of objects in 3-D scenes (see, e.g., Feria, Braunstein, & Andersen, 2003;Meng & Sedgwick, 2001Ni, Braunstein, & Andersen, 2004, 2007Sauer, Braunstein, Saidpour, & Andersen, 2002;Sinai, Ooi, & Z. J. He, 1998;.…”

Perceptual slant induced through optical contact

“…The three kinds of distance generally differ from may intervene as the mediators in the propagation process (cf. Albert, 1999;Reinhardt-Rutland, 1999;Sauer, Braunstein, Saidpour, & Andersen, 2002); the process may involve more than two parts in the image that, in terms of optical contact, are linked to form chains or hierarchies (nested contact relations; cf. Meng & Sedgwick, 2001, 2002Ni, Braunstein, & Andersen, 2005).…”