Structure-preserving noise reduction in biological Imaging

An approach for noise filtering based on anisotropic nonlinear diffusion is presented. The method combines edge-preserving noise reduction with a strategy to enhance local structures and a mechanism to further smooth the background. The performance is illustrated with its application to electron cryotomography, a leading imaging technique for visualizing the molecular architecture of complex biological specimens. A challenging task in this discipline is to increase the extremely low signal-to-noise ratio to allow visualization and interpretation of the three-dimensional structures. The filtering method presented here succeeds in substantially reducing the noise with excellent preservation of the structures.