Finding axes of skewed symmetry

A bilaterally symmetric figure on an arbitrarily oriented plane viewed under orthographic projection yields a “skew symmetric” figure whose axes of symmetry and skew constrain the orientation of the underlying plane. Detection of skewed symmetries and extraction of axis orientations constitute a necessary practical issue that has not received much attention. We develop a strong necessary condition on the axes of symmetry and skew in a planar skew symmetric figure which constrains, them to lie on a one-dimensional locus in a two-dimensional space of orientation pairs. The practicality of our technique is demonstrated with illustrations from an experimental testbed. A heuristic symmetry evaluator is used in conjunction with our constraint to determine axes of skewed symmetry.