This Node implements the so-called anisotropic diffusion scheme of Perona and Malik, 1990. For details on the anisotropic diffusion principles, see: http://en.wikipedia.org/wiki/Anisotropic_diffusion, and the original paper: Perona and Malik. Scale-Space and Edge Detection Using Anisotropic Diffusion. IEEE Transactions on Pattern Analysis and Machine Intelligence (1990) vol. 12 pp. 629-639