Fig. 13
From: Stopping criterion for linear anisotropic image diffusion: a fingerprint image enhancement case
Comparison between spatial entropy-based and correlation-based stopping rule. a displays spatial entropy change graph of an acquired digital fingerprint as black curve and correlation coefficient between (input noisy image - diffused image) and diffused image. b shows stopping the diffusion process at the minimum of the correlation coefficient curve. The diffused image still shows signs of interrupted ridges