Our approach to three dimensional nonlinear noise reduction filters, such as bilateral pre-filtering coupled with an evolution driven anisotropic geometric diffusion PDE (partial differential equation), have shown significant results in enhancing the visualization of macromolecular tomographic imaging. The PDE model is :

The efficacy of our method is based on a careful selection of the anisotropic diffusion tensor based on estimates of the normal and two principal curvatures and curvature directions of a feature isosurface in three dimensions.