Application of level set method to detect soma area.

<p>The figure shows a detail from a segmented image of a neuron (MIP) where colors correspond to the values of the Directional Ratio values and range between 1 (=red) and 0 (=blue). The application of the threshold value 0.9 identifies a region strictly inside the soma, with boundary curve Γ (in the left panel). The level set method evolves the boundary curve Γ with a velocity in the normal direction (indicated by the arrows in the right panel) that depends on the magnitude of the gradient of the Directional Ratio.