A Fast Hadamard Transform for Signals With Sublinear Sparsity in the Transform Domain

A Robust Image Denoising Technique in the Contourlet Transform Domain

The contourlet transform has the benefit of efficiently capturing the oriented geometrical structures of images. In this paper, by incorporating the ideas of Stein’s Unbiased Risk Estimator (SURE) approach in Nonsubsampled Contourlet Transform (NSCT) domain, a new image denoising technique is devised. We utilize the characteristics of NSCT coefficients in high and low subbands and apply SURE sh...

Quasi-cyclic dyadic codes in the Walsh--Hadamard transform domain

A code is -quasi-cyclic ( -QC) if there is an integer such that cyclic shift of a codeword by -positions is also a codeword. For = 1, cyclic codes are obtained. A dyadic code is a code which is closed under all dyadic shifts. An -QC dyadic ( -QCD) code is one which is both -QC and dyadic. QCD codes with = 1 give codes that are cyclic and dyadic (CD). In this correspondence, we obtain a simple c...

Fast MIR in a Sparse Transform Domain

We consider in this paper sparse audio coding as an alternative to transform audio coding for efficient MIR in the transform domain. We use an existing audio coder based on a sparse representation in a union of MDCT bases, and propose a fast algorithm to compute mid-level representations for beat tracking and chord recognition, respectively an onset detection function and a chromagram. The resu...

Hadamard Transform for Speech Wave

Construction of DC-free Codes Using the Fast Hadamard Transform

We report on new class of dc-free codes that use the Fast Hadamard Transform (FHT) to evaluate a selection set of candidate codewords. The codeword with the least contribution to the low-frequency content is transmitted. The FHT makes it possible to e ciently evaluate the selection set of candidate codewords. Spectral properties of the new codes have been evaluated by computer simulation.