The contributions of slant and tilt to the detection of local surface orientation in structure from motion

Abstract

The contribution of slant and tilt to the detection of differences in local surface orientation was examined for structure-from-motion (SFM) displays of a complex sinusoidal surface. Observers judged whether an elliptical SFM gauge figure appeared to be lying on the surface or intersecting it. The gauge figure orientation either matched the local surface orientation or differed from it in slant, tilt, or both. Similar sensitivity was found for deviations in slant and tilt, but greater biases and variability were found when the gauge figure deviated from the local surface orientation in slant, depending on the sign of the difference between the gauge figure and local surface orientation and the position of the gauge figure. The results are consistent with Stevens' (Biological Cybernetics, 46 (1983) 183-195) discussion of the computational advantages of slant and tilt contributing independently to the detection of differences in local surface orientation. The effects of changes in perceived surface slant and tilt during rotation and of the misperception of surface depth on the detection of local orientation in dynamic images are discussed.

The visual perception of 3-D shape from multiple cues: Are observers capable of perceiving metric structure?

“…There have been a few experiments reported in the literature in which human observers have made accurate judgments of 3-D metric structure from motion (Johnston et al, 1994;Lappin & Ahlström, 1994;Lappin & Love, 1992), but they have all involved one of the two special cases identified above. A more typical result in the vast majority of experiments on this topic is that judged metrical relations almost always deviate significantly from the physically specified structure and that they are often unreliable as well (Bocheva & Braunstein, 2000;Bradshaw et al, 2000;Braunstein & Andersen, 1984;Braunstein et al, 1993;Braunstein & Tittle, 1988;Caudek & Proffitt, 1993;Cornilleau-Pérès & Droulez, 1989;Domini & Braunstein, 1998;Domini & Caudek, 1999;Domini, Caudek, & Proffitt, 1997;Durgin et al, 1995;Eagle & Blake, 1995;Hogervorst & Eagle, 1998;Liter & Braunstein, 1998;Liter, Braunstein, & Hoffman, 1993;Loomis & Eby, 1988Norman & Lappin, 1992;Norman & Todd, 1993;Norman, Todd, & Phillips, 1995;Perotti, Todd, Lappin, & Phillips, 1998;Tittle et al, 1995;Todd, 1984Todd, , 1985Todd & Bressan, 1990;Todd & Norman, 1991;Todd & Perotti, 1999;Turner & Braunstein, 1995;Werkhoven & van Veen, 1995). The relative scaling of height, width, and depth reported in these studies can vary dramatically depending on the details of each individual experiment.…”