Topic
Quadrature mirror filter
About: Quadrature mirror filter is a research topic. Over the lifetime, 955 publications have been published within this topic receiving 28900 citations.
Papers published on a yearly basis
Papers
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TL;DR: In this work, two-channel perfect reconstruction quadrature mirror filter (QMF) bank has been proposed based on the prototype filter using windowing method and the results are provided and compared with the existing methods.
Abstract: In this work, two-channel perfect reconstruction quadrature mirror filter (QMF) bank has been proposed based on the prototype filter using windowing method. A novel window function based on logarithmic function along with the spline function is utilized for the design of prototype filter. The proposed window has a variable parameter ‘
$$\alpha $$
’, which varies the peak side lobe level and rate of fall-off side lobe level which in turn affects the peak reconstruction error (PRE) and amplitude distortion (
$$e_{am}$$
) of the QMF bank . The transition width of the prototype is controlled by the spline function using the parameter ‘
$$\mu $$
’. The perfect reconstruction condition is satisfied by setting the cutoff frequency (
$$\omega _{c}$$
) of the prototype low-pass filter at ‘
$$\pi /2$$
’. The performance of the proposed design method has been evaluated in terms of mean square error in the pass band, mean square error in the stop band, first side lobe attenuation (
$$A_{1}$$
), peak reconstruction error (PRE) and amplitude error (
$$e_{am}$$
) for different values of ‘
$$\alpha $$
’ and ‘
$$\mu $$
’. The results are provided and compared with the existing methods.
7 citations
01 Jan 1993
TL;DR: This work has shown that nonuniform analysis-synthesis systems based on maximally decimated filter banks in which the bandwidths of the channels increase with increasing frequency are best met.
Abstract: Over the last decade, analysis-synthesis systems based on maximally decimated filter banks have emerged as one of the important techniques for speech and audio coding. For speech and audio signals, the analysis-synthesis filter bank can be thought of as modeling the human auditory system, where the critical band model of aural perception is reflected in the design of the filter banks. The constraints imposed by the aural model are best met by nonuniform analysis-synthesis systems in which the bandwidths of the channels increase with increasing frequency.
7 citations
TL;DR: In this article, the performance of a multirate sub-band adaptive beamforming array with different filter order of the QMF banks but fixed number of sub-bands was investigated.
Abstract: An investigation into the performance of a multirate sub-band adaptive beamforming array is carried out. Quadrature mirror filter (QMF) banks are used here to partition the frequency band, rather than the conventional Fast Fourier transform (FFT) algorithm. The MSE performances for the sub-band adaptive beamformer with (i) different filter order of the QMF banks but fixed number of sub-bands and (ii) fixed length of the QMF bank but different number of sub-bands are analysed. Both cases show reduction in MSE as either the QMF order is increased or the number of bands is increased. The selection of the QMF bank and the number of bands are left to the user, depending upon the computational complexity and implementation cost. Two examples are chosen from the above analysis and further investigations are carried out on them. The behaviour of the different structures, in terms of eigenvalue performance, radiation characteristics and mean square errors (MSE) are studied and analysed. The filter orders used are ...
7 citations
09 May 1995
TL;DR: In this paper, the use of a paraunitary filter bank for image processing requires a special treatment at image boundaries to ensure perfect reconstruction and orthogonality of these regions.
Abstract: The use of a paraunitary filter bank for image processing requires a special treatment at image boundaries to ensure perfect reconstruction and orthogonality of these regions. Using time-varying boundary filter banks, we will discuss a procedure that explores all degrees of freedom of the border filters in a method essentially independent of signal extensions, allowing us to design optimal boundary filter banks, while maintaining fast implementation algorithms.
7 citations
14 Nov 2005
TL;DR: This paper introduces a family of non-adaptive geometrical wavelets that have high anisotropy and directionality and derive from a single non-separable filter bank structure that is designed from 1-D and quincunx filters.
Abstract: This paper introduces a family of non-adaptive geometrical wavelets that have high anisotropy and directionality. Unlike curvelets and contourlets, they have no redundancy and form orthonormal bases of L/sup 2/ (R/sup 2/). Their implementation derives from a single non-separable filter bank structure that is designed from 1-D and quincunx filters.
7 citations