QUASI-INVARIANT PARAMETERISATIONS AND MATCHING OF CURVES IN IMAGES

In this paper, we investigate quasi-invariance on a smooth manifold, a nd show that there exist quasi-invariant parameterisations which are n ot exactly invariant but approximately invariant under group transform ations and do not require high order derivatives. The affine quasi-inv ariant parameterisation is investigated in more detail and exploited f or defining general affine semi-local invariants from second order der ivatives only. The new invariants are implemented and used for matchin g curve segments under general affine motions and extracting symmetry axes of objects with 3D bilateral symmetry.