Mixed anisotropic diffusion

This paper deals with the filtering and the enhancement of strongly oriented patterns. We propose a new filter combining scalar and tensor based diffusivities. The computation of an orientation confidence allows its to choose the best strategy to locally diffuse the gray levels. We show that this approach overcomes some drawbacks of the classical methods like corner smoothing or pinhole effect. The proposed method was applied on digital images of engravings. This type of images contain strongly oriented patterns and a large amount of details that have to be preserved during the diffusion.