Following recent work on Curvelet Reconstruction with
Sparsity-promoting Inversion (CRSI - Herrmann and Hennenfent, 2007), seismic
wavefields are reconstructed via
where
s.t.
(9)
In this formulation,
is the discrete wrapping-based
curvelet transform (Candès et al., 2005a). Similarly to any other
data-independent transforms, curvelets do not provide a sparse
representation of seismic data in the strict sense. Instead, the
curvelet transform provides a compressible, arguably the most
compressible (Hennenfent and Herrmann, 2006), representation.
Compressibility means that most of the wavefield energy is captured by
a few significant coefficients in the sparsifying domain. Since CS
guarantees, for sparse-enough signal representations, the recovery of
a fixed number of largest coefficients for a given undersampling
factor (Candès et al., 2005b), a more compressible representation yields
a better reconstruction, which explains the success of CRSI.
Subsections