Fig. 11
From: Stopping criterion for linear anisotropic image diffusion: a fingerprint image enhancement case
Validation test for homomorphic filtering output. a shows the binarization of an acquired digital fingerprint using the optimal Otsu method. b depicts the binarization of the uniformly illuminated fingerprint with homomorphic filtering, also using the optimal Otsu method. We observe that binarization results for filtering output shows all the regions with ridge/valley structure intact