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From: gh@utai.UUCP (Graeme Hirst)
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Subject: A.I. seminar, Univ Toronto: Chris Brown (Rochester)
Message-ID: <254@utai.UUCP>
Date: Thu, 4-Oct-84 09:56:23 EDT
Article-I.D.: utai.254
Posted: Thu Oct  4 09:56:23 1984
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Organization: CSRI, University of Toronto
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.		ARTIFICIAL INTELLIGENCE SEMINAR
		DEPARTMENT OF COMPUTER SCIENCE
		     UNIVERSITY OF TORONTO

	  Skewed symmetry: Its physiology and technique
			   Chris Brown
		    University of Rochester

	  Tuesday 9 October, 3pm, Sandford Fleming 1105


			     ABSTRACT

Symmetric planar shapes viewed under orthography from an arbitrary position
have a (skewed) symmetry axis and a skew (transverse) axis.  If thye are known,
th plane's orientation may be constrained to a one-dimensional locus in the
spherical space of orientations.

The second moments of skew-symmetric image shapes constrain the axes to a
one-dimensional locus in the toroidal space of axis-angle pairs.  Then finding
skew and symmetry axes involves searching this locus for a pair of angles that
in fact specify satisfactory axes.  In a quantized image, this calls for robust
symmetry evaluators.

The analytic constraints will be developed, several symmetry evaluators
considered, and experimental results shown.
-- 
\\\\   Graeme Hirst    University of Toronto	Computer Science Department
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