Dale J. Shpak

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The design and implementation of reversible wavelet/subband transforms and their application to reversible embedded image compression are studied. Reversible embedded image coding provides a natural way for building uni ed lossy/lossless image compression systems, and reversible transforms are a key component in such systems. A lifting-based method is(More)
A new optimization method for the design of fullband and lowpass IIR digital differentiators is proposed. In the new method, the passband phase-response error is minimized under the constraint that the maximum passband amplitude-response relative error is below a prescribed level. For lowpass IIR differentiators, an additional constraint is introduced to(More)
A new optimization method for the design of nearly linear-phase IIR digital filters that satisfy prescribed specifications is proposed. The group-delay deviation is minimized under the constraint that the passband ripple and stopband attenuation are within the prescribed specifications and either a prescribed or an optimized group delay can be achieved. By(More)
A new method for designing non-uniform filterbanks for acoustic echo cancellation is proposed. In the method, the analysis prototype filter design is framed as a convex optimization problem that maximizes the signal-to-alias ratio (SAR) in the analysis banks. Since each sub-band has a different bandwidth, the contribution to the overall SAR from each(More)
An approach for detecting and removing impulse noise from speech using the wavelet transform is proposed. The approach utilizes the multi-resolution property of the wavelet transform, which provides finer time resolution at higher frequencies than the short-time Fourier transform to effectively identify and remove impulse noise. The paper then describes how(More)
Abstract—A new method for designing non-uniform filterbanks for acoustic echo cancellation is proposed. In the method, the analysis prototype filter design is framed as a convex optimization problem that maximizes the signal to alias ratio (SAR) in the analysis banks. Since each sub-band has a different bandwidth, the contribution to the overall SAR from(More)
A new method for the design of linear-phase robust far-field broadband beamformers using constrained optimization is proposed. In the method, the maximum passband ripple and minimum stopband attenuation are ensured to be within prescribed levels, while at the same time maintaining a good linear-phase characteristic at a prescribed group delay in the(More)
An algorithm that reduces the computational load in near-end crosstalk (NEXT) cancellation in xDSL systems is proposed. The Section 3 presents an algorithm that minimizes the number of filter taps under the constraint that the maximum crosstalk noise be below a given threshold. 2. FILTER-TAP MINIMIZATION algorithm adjusts the length of each adaptive filter(More)
A methodology for the design of recursive digital filters having nearly linear phase response is proposed. The underlying design method is of the direct type whereby the filter is designed as a single unit. The design problem is formulated as a cascade of filter sections where each section is represented by a biquadratic transfer function either in the(More)