A Robust Corner Matching Technique

In contour-based comer detectors, absolute curvature values of many corners either remain unaltered or change slightly under affine transformations. Moreover, affine-length of a curve is relatively invariant to affine transformations. This paper presents a novel corner matching technique using corners detected by contour-based detectors. For each corner we use its position, absolute curvature value, and affine-lengths between this corner and other corners on the same curve. The iterative matching procedure tries to find three corner matches with minimum absolute curvature difference to calculate affine transformation parameters. Original corners are transformed with the estimated parameters prior to matching with the test corner set.