Gradient-based enhancement of tubular structures in medical images
A radial function is used to filter out gradients not pointing to the center. Spherical harmonics are used to detect ring patterns in the distribution of gradient. Evenness, uniformness and structuredness is estimated from the power spectrum in SH. Vesselness combines these features using sigmoid functions. The proposed method performs better than the state-of-the-art.
spherical harmonics vesselness structure tensor