The picture on the right shows the second dyadic decomposition
(SDD), which is also the frequency partitioning of curvelets.
The SDD
was invented by Charles Fefferman in 1973 to answer mathematical
questions of boundedness of Bochner-Riesz summation multipliers
(some convolution operators).
Next, we show examples
of curvelets at different scales, both in space
and frequency.
Finally,
the picture on the right shows the second dyadic decomposition
in three dimensions, which is also the frequency partitioning
of 3d curvelets.