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Proceedings Paper

Symmetry detection in 3D scenes
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Paper Abstract

Retinal image of a symmetric object is itself symmetric only for a small set of viewing directions. Interestingly, human subjects have little difficulty in determining whether a given retinal image was produced by a symmetric object, regardless of the viewing direction. We tested perception of planar (2D) symmetric figures (dotted patterns and polygons) when the figures were slanted in depth. We found that symmetry could be detected reliably with polygons, but not with dotted patterns. Next, we tested the role image features representing the symmetry of the pattern itself (orientation of projected symmetry axis and symmetry lines) vs. those representing the 3D viewing direction (orientation of the axis of rotation). We found that symmetry detection is improved when the projected symmetry axis or lines are known to the subject, but not when the axis of rotation is known. Finally, we showed that performance with orthographic images is higher than that with perspective images. A computational model, which measures the asymmetry of the presented polygon based on its single orthographic or perspective image, is presented. Performance of the model is similar to the performance of human subjects.

Paper Details

Date Published: 28 February 2007
PDF: 12 pages
Proc. SPIE 6498, Computational Imaging V, 64980Y (28 February 2007); doi: 10.1117/12.715160
Show Author Affiliations
Tadamasa Sawada, Purdue Univ. (United States)
Zygmunt Pizlo, Purdue Univ. (United States)


Published in SPIE Proceedings Vol. 6498:
Computational Imaging V
Charles A. Bouman; Eric L. Miller; Ilya Pollak, Editor(s)

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