Fig. 7

Linear anisotropic diffusion process. a shows a flow-like test image having three black curves with a white background. The features present in the image are elongated in shape with a constant width of two pixels. b shows the smooth spatial entropy graph resulting from diffusion process with respect to the natural scale parameter. The entropy change with natural scale change is displayed in (c), where the peak corresponds to the width of the curves. 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 the binary image using Otsu optimal threshold of 0.63, as shown in (e)