  We introduce an approach based on moving frames for polygon recognition and
symmetry detection. We present detailed algorithms for recognition of polygons
modulo the special Euclidean, Euclidean, equi-affine, skewed-affine and
similarity Lie groups, and explain the procedure for a generic Lie group. The
time complexity of our algorithms is linear in the number of vertices and they
are noise resistant. The signatures used allow the detection of partial as well
as approximate equivalences. Our method is a particular case of a general
method for curve recognition modulo Lie group action.
