Diffusion smoothing on manifolds

To increase the signal to noise ratio (SNR) on the brain surface, diffusion smoothing has been applied via the finite element method (FEM) on the triangular mesh. The mean curvature has been computed. Without surface-based smoothing, it is almost impossible to get consistent less noise consistent sulcal pattern. One way to get very smooth sulcal pattern is to do mesh smoothing via Laplace smoothing; however, it more or less distorts the geometry.