Wreath Product Group Transform
In the recent paper "A Wreath Product Approach to Signal and Image Processing: Part I --- Multiresolution Analysis", by Foote, Mirchandini, Rockmore, Healy, and Olson, IEEE Trans. on Signal Processing, Vol. 48, pp. 102--132, transforms arising from iterated wreath products of cyclic groups have been proposed for image processing. The following structured, sparse matrix factorization represents a fast algorithm for a wreath product transform of size 16 (given on p. 117 of the paper), and has been automatically generated (even in the presented Latex format) using the package AREP.
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