Dale J. Shpak

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—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 1 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)
—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)
The design and implementation of reversible wavelettsubband transforms and their application to reversible embedded image compression are studied. Reversible embedded image coding provides a natural way for building uniied lossyylossless image compression systems, and reversible transforms a r e a k ey component i n s u c h systems. A lifting-based method(More)
| A VLSI architecture designed to perform real-time image compression using wavelets is described. The two basic modules of the architecture are a 2-D wavelet transform generator and a coder based on the SPIHT algorithm for lossy image compression. A folded architecture is proposed for computing the 2-D wavelet transform. The architecture uses 3 parallel(More)
— A new method for designing non-uniform filter-banks for acoustic echo cancelation is proposed. In the method, the analysis prototype filter design is framed as a bi-criterion optimization problem that minimizes the aliasing power while maximizing the bandwidth. Consequently, an optimal trade-off curve between filter bandwidth and aliasing power is(More)
— A new method for designing non-uniform filter-banks 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)
—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 bi-quadratic transfer function either in the(More)