public static interface AnisotropicDiffusion.DiffusionFunction

The interface that function suitable to be diffusion function must implement. It is very simple and has some limitation: in Perona & Malik scheme, the gradient at each arc location is approximated by the absolute value of its projection along the direction of the arc (see paper, p. 633). Functions implementing this interface are therefore provided only with a single component of the gradient, and must return the diffusion contribution in that direction.