Figure 4.

Segmentation results from the phantom image. (a) On noise-free images, Boykov's boundary term favoring high contrast [Eq. 5] is prone to leakage if a high contrast boundary is present in nearby tissue (arrow). (b) Additional brush strokes are needed to exclude neighboring tissue. (c) On an image with 4% Gaussian noise, using Boykov's boundary term and strongly weighted regional term results in an irregular boundary and pixels within the segmentation are excluded. (d) In contrast, our method SAASS requires fewer brush strokes and preserves piece-wise continuity.