In this paper we study some statistics linked to the average of Lipschitz-Killing (LK) curvatures of the excursion set of a stationary non-standard isotropic Gaussian field X on R 2. Under this hypothesis of unknown location and scale parameters of X, we introduce novel fundamental quantities, that we call effective level and effective spectral moment, and we derive unbiased and asymptotically normal estimators of these parameters. Furthermore, empirical variance estimators of the asymptotic variance of the third LK curvature of the excursion set (i.e., the area) and of the effective level are proposed. Their consistency is established under a weak condition on the correlation function of X. Finally, using the previous asymptotic results, we built a test to determine if two images of excursion sets can be compared. This test is applied on both synthesized and real mammograms.