Fig. 8

Linear anisotropic diffusion process for noisy image. a shows a flow-like noisy test image having three black curves with a white background. The Gaussian noise is added to bring down the SNR of the resulting image to be −10 dB. b shows the smooth spatial entropy graph resulting from diffusion process on the natural scale parameter. The entropy change with natural scale change is displayed in (c), where a distinct peak is still observable. The diffused image resulting from stopping the diffusion process at the location of the peak in entropy change is shown in (d). The diffused image is converted to binary image using Otsu optimal threshold of 0.55, as shown in (e)