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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
More filters
Proceedings ArticleDOI
26 Apr 1985
TL;DR: It is shown that the original signal decomposed by the analysis filter bank into N adjacent uniform subbands subsampled by N, can be reconstructed with negligible distortion.
Abstract: This paper introduces a flexible design method of computationally efficient uniform filter bank where each filter channel is obtained by frequency translation of a prototype base-band filter. It is shown that the original signal decomposed by the analysis filter bank into N adjacent uniform subbands subsampled by N, can be reconstructed with negligible distortion. We give a practical implementation which allows an important reduction in computational complexity. It can be therefore applied to such signal processing tasks as speech coding or spectral parametrization of signals.

67 citations

Journal ArticleDOI
TL;DR: The authors analyze the coding errors due to quantization by explicitly incorporating a mathematical model for a Lloyd-Max quantizer into a quadrature mirror filter (QMF) splitting and reconstruction scheme by means of a quantizer model, which makes it possible to discriminate between different types of coding errors.
Abstract: The authors analyze the coding errors due to quantization by explicitly incorporating a mathematical model for a Lloyd-Max quantizer into a quadrature mirror filter (QMF) splitting and reconstruction scheme (P. H. Westerink et al., 1988). This approach explicitly incorporates quantization errors into a QMF system by means of a quantizer model. This makes it possible to discriminate between different types of coding errors, such as the aliasing error. Other errors that can be distinguished are a QMF design error, a signal error, and a random error, which is uncorrelated with the original image. Both a mean-squared error calculation and a subjective judgment of the coding errors show that the aliasing errors can be neglected for filter lengths of 12 taps or more. The signal error determines the sharpness of the reconstructed image, while the random error is most visible in the flat areas. >

66 citations

Patent
18 Mar 1993
TL;DR: In this article, the Multiplierless Quadrature Mirror Filter concept is used in the design of analysis and synthesis filter banks to be used for the sub-band coding of various types of signals.
Abstract: The Multiplierless Quadrature Mirror Filter concept is used in the design of analysis and synthesis filter banks to be used for the sub-band coding of various types of signals. The individual filters in the analysis and synthesis filter banks are designed to be near linear in phase, non-symmetrical in time, and to have equal bandwidth frequency responses. These multiplierless filters are relatively easy to implement in hardware and allow for the sub-band coding of signals with minimal computational complexity so as to result perfect signal reconstruction. Furthermore, these filters are particularly well suited for configuration in hierarchical sub-band structures.

64 citations

BookDOI
01 Jan 2001
TL;DR: The intention of this paper is to pro vide an elementary introduction to the subject of discret e-t ime wavelets and reviews t heir properties in a syste mat ic and consiste nt way.
Abstract: The intention of this paper is to pro vide an elementary introduction to the subject of discret e-time wavelets. It defines the discret e-t ime wavelet s and reviews t heir properties in a syste mat ic and consiste nt way. Different kinds of ort hogona lity between the wavelets are addressed and the corres pond ing sufficient and necessary condit ions ar e derived . It is shown when discret e-t ime wavelets can be samples of continuous-t ime wavelet s. The condit ions for shift-invari an ce of discrete-time wavelet representations are given in det ail. The appearance of two biorthogonal representation sets of discrete-ti me wavelet s from t he binary subband decomposition /reconstruction of signals is pointed out . When t he numher of different representation scales is finit e, it is shown that in order to obtain the orthogonality betwe en wavelet s, the known requircm cnt for wavelet generating filter can be relaxed .

64 citations

Journal ArticleDOI
TL;DR: By defining pitch-synchronous wavelets based on warped wavelets, the analysis of transients and denoising of inharmonic pseudo-periodic signals is greatly enhanced by means of rational transfer functions.
Abstract: We extend the definition of dyadic wavelets to include frequency warped wavelets. The new wavelets are generated and the transform computed in discrete-time by alternating the Laguerre transform with perfect reconstruction filterbanks. This scheme provides the unique implementation of orthogonal or biorthogonal warped wavelets by means of rational transfer functions. We show that the discrete-time warped wavelets lead to well-defined continuous-time wavelet bases, satisfying a warped form of the two-scale equation. The shape of the wavelets is not invariant by translation. Rather, the "wavelet translates" are obtained from one another by allpass filtering. We show that the phase of the delay element is asymptotically a fractal. A feature of the warped wavelet transform is that the cut-off frequencies of the wavelets may be arbitrarily assigned while preserving a dyadic structure. The new transform provides an arbitrary tiling of the time-frequency plane, which can be designed by selecting as little as a single parameter. This feature is particularly desirable in cochlear and perceptual models of speech and music, where accurate bandwidth selection is an issue. As our examples show, by defining pitch-synchronous wavelets based on warped wavelets, the analysis of transients and denoising of inharmonic pseudo-periodic signals is greatly enhanced.

64 citations

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231
20227
20214
20203
20197
201812