Figure 4

Segmentations of four models for four real images with non-uniform backgrounds, starting with a constant function${\mathbf{\psi }}_{\mathbf{0}}\mathbf{=}\mathbf{2}$. (a)-(d): original images. (e)-(h): results of the Canny algorithm (left to right: $\sigma =1,T=\left[0\text{.02,}0.2\right]$; $\sigma =1,T=\left[0\text{.2,}0.3\right]$; $\sigma =2.2,T=\left[0\text{.09,}0.7\right]$; $\sigma =2.2,T=\left[0\text{.09,}0.4\right]$). (i)-(l): results of the CV model (5, 5, 300, 500 iterations). (m)-(p): results of the RSF model (left to right: $\nu =0.01\times 255\times 255$with 300 iterations, $\nu =0.008\times 255\times 255$with 560 iterations, ${\lambda }_2=1.2,\nu =0.008\times 255\times 255$ with 300 iterations, $\nu =0.004\times 255\times 255$ with 300 iterations). (q)-(t): results of our model (12, 24, 45, 87 iterations). (u) and (x): 3D plots of final level set functions.