Shearlet theory has become a central tool in analyzing and representing 2D
data with anisotropic features. Shearlet systems are systems of functions
generated by one single generator with parabolic scaling, shearing, and
translation operators applied to it, in much the same way wavelet systems are
dyadic scalings and translations of a single function, but including a precise
control of directionality. Of the many directional representation systems
proposed in the last decade, shearlets are among the most versatile and
successful systems.