摘要 |
Fast digital implementations of the second generation curvelet transform for use in data processing are disclosed. One such digital transformation is based on unequally-spaced fast Fourier transforms (USFFT) while another is based on the wrapping of specially selected Fourier samples. Both digital transformations return a table of digital curvelet coefficients indexed by a scale parameter, an orientation parameter, and a spatial location parameter. Both implementations are fast in the sense that they run in about O(n<SUP>2 </SUP>log n) flops for n by n Cartesian arrays or about O(N log N) flops for Cartesian arrays of size N=n<SUP>3</SUP>; in addition, they are also invertible, with rapid inversion algorithms of about the same complexity.
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