Figure 6
Scheme for the shape reconstruction routine of VM_SCS.
(a) The sphere coordinate system with origin position O used to describe the signal from the image stacks. (b) The normalized signals in rays obtained via data sampling in sphere coordinate system. For each ray, it was equally divided into 39 parts and its signal is generated by averaging the signals of each dividing point (including endpoints) and its 6 neighbors. (c) The valid gradient signal of each ray was calculated from the curve in (b) with respect to the same ray and generated by setting the negative value of the smoothing gradient signal to its converse value and setting the positive value to zero. The red curves in (b) and (c), corresponding to the red ray OP in (a), served as an example for illustrating how to obtain the gradient signal. (d) By iteratively computing the equation (7), which can minimize the energy function, the curve surface in sphere coordinate system was obtained from the signals in (c). The third component value of a point in the curve surface is the distance between the computed boundary position to origin position O in the ray determined by the others components i.e., polar angle and azimuth angle. (e) Soma shape formed by the computed boundary positions in the rays.
