]>Shells and Spheres: An <i>n</i>-Dimensional Framework for Medial-Based Image Segmentation : Figure 9
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Figure 9: A height map of the variance 𝜎 2 ( 𝐱 ) after Step 1 is applied to the image in Figure 8, showing large spikes where spheres encounter two boundaries at once, canceling VSS gradient and growing too large.