Fig. 14

Progression of diffusion for a fingerprint image. Image binarized using global threshold using the Otsu method with respect to various locations of the entropy-change graph. a displays image at τ=−1.2, the location specified by the correlation method. Similarly, (b) at τ=0.9, (c) at τ = 1, (d) at τ = 1.1, (e) at τ=1.4, and (f) at t a u=2. We observe that as the diffusion increases, the the gaps within ridges started to fill. However, after a certain limit as τ=1, the closer ridges started to get merged into one. The ellipse is drawn of the portion of the fingerprint to facilitate observation