A Note on Differential Corner Measures

The isophote curvature times the gradient magnitude to some power has been studied in the literature as a measure of cornerness in images, and stability in terms of sampling noise has been proposed by selecting corners in these measures at high scale and locating them at fine scale. We will examine the problem of tracking extrema of these measures in the Linear Scale-Space and conclude that annihilations and creations generically occurs, so that corners in general cannot be tracked to arbitrarily fine/coarse scale. However, there are quantitatively differences, and the analysis indicates that isophote curvature times the gradient magnitude is best suited for binary images. 1. Introduction The literature on corner detection roughly divides into two classes. Some use explicit models, see e.g. [7] for an overview. Others use derivative expressions like the Gaussian curvature, the structure tensor (the interest operator, second moment matrix), expressions involving the isophote curvature,..