The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
P.p. Vaidyanathan - One of the best experts on this subject based on the ideXlab platform.
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Perfect Reconstruction QMF structures which yield linear phase FIR analysis filters
1988. IEEE International Symposium on Circuits and Systems, 1Co-Authors: Truong Q. Nguyen, P.p. VaidyanathanAbstract:The authors present a Perfect Reconstruction FIR (finite-impulse response) linear-phase lattice structure for the two-channel quadrature-mirror-filter (QMF) bank. This structure covers most pairs of Perfect Reconstruction FIR linear-phase analysis filters which have the same (odd) order. For general number of channels M, conditions are derived which any QMF Perfect Reconstruction linear phase structure must obey. A design example is presented for the M=2 case. >
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ICASSP - The Perfect-Reconstruction QMF bank: New architectures, solutions, and optimization strategies
ICASSP '87. IEEE International Conference on Acoustics Speech and Signal Processing, 1Co-Authors: P.p. Vaidyanathan, Phuong-quan HoangAbstract:In this paper, a scheme for Perfect Reconstruction in M channel, maximally decimated QMF banks is first presented, for arbitrary M. The solutions are such that the analysis and synthesis filters are FIR and of the same length. Based on the theory, lattice structures for the two-channel case are derived, which offer an efficient design as well as implementation procedure for two-channel Perfect Reconstruction systems. Such lattice implementations are robust in the sense that the Perfect-Reconstruction property is preserved in spite of coefficient quantization.
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How to capture all FIR Perfect Reconstruction QMF banks with unimodular matrices
IEEE International Symposium on Circuits and Systems, 1Co-Authors: P.p. VaidyanathanAbstract:The problem of Perfect Reconstruction in maximally decimated FIR (finite impulse response) QMF (quadrature mirror filter) banks is revisited. A necessary and sufficient condition for Perfect Reconstruction in this system is that the polyphase matrix of the analysis bank must have a determinant equal to a delay. The author explores various avenues to completely parameterize such matrices. It is shown that the problem can always be decomposed into two problems: one of parameterizing lossless matrices, and one of parameterizing unimodular matrices. Several possibilities for unimodular parameterization are explored. >
Masaaki Ikehara - One of the best experts on this subject based on the ideXlab platform.
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Design of oversampled Perfect Reconstruction FIR filter banks
Electronics and Communications in Japan (Part III: Fundamental Electronic Science), 1997Co-Authors: Takayuki Nagai, Masaaki IkeharaAbstract:There are some applications that require oversampled filter banks, for example, adaptive signal processing using multirate filter banks. Little study was done, however, for such filter banks compared with maximally decimated ones. In this paper, we propose a design method for oversampled filter banks which satisfy the Perfect Reconstruction and linear phase properties. Moreover, we consider the design method for both orthogonal and biorthogonal ones. When the decimation ratio is not a divisor of the number of channels, we find it impossible for analysis and synthesis filters to have the same frequency responses by considering the mechanism of aliasing cancellation. In other words, biorthogonal filter banks can be designed under an arbitrary decimation ratio, while it is restricted to a divisor of the number of channels in the orthogonal case. We first derive the conditions for Perfect Reconstruction and linear phase for both biorthogonal and orthogonal ones. Then, we present the design method for both cases. Finally, some design examples are shown. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 3, 80(10): 78–86, 1997
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Design of Two-Channel Perfect Reconstruction QMF
Electronics and Communications in Japan (Part III: Fundamental Electronic Science), 1993Co-Authors: Masaaki Ikehara, Akinobu Yamashita, Hideo KurodaAbstract:This paper proposes a design method for the FIR two-channel Perfect quadrature mirror filter (QMF) with the linear phase. The two-channel Perfect QMF can be designed by Vetterli's method, where a system of equations representing the condition for the Perfect Reconstruction of the signal is solved. The filter designed by this method, however, does not, in general, have good frequency characteristics. This paper presents the design for the two-channel QMF with a Perfect Reconstruction and a good amplitude characteristic. The method is based on Vetterli's method, and a constraint to approximate the amplitude characteristic in the frequency domain is added to the condition of Perfect Reconstruction in time domain. Then Remez' algorithm is applied to the derived system of equations. The construction of the two-channel Perfect QMF, when the coefficient is quantized, also is discussed. Furthermore, a method is shown in which the two-dimensional (2-D) Perfect QMF is designed by applying the McClellan transformation to the obtained 1-D QMF. The condition for the McClellan transformation for the Perfect Reconstruction is derived.
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Design of causal IIR filter banks satisfying Perfect Reconstruction
Proceedings of 1997 IEEE International Symposium on Circuits and Systems. Circuits and Systems in the Information Age ISCAS '97, 1Co-Authors: Masahiro Okuda, Masaaki Ikehara, Takashi Fukuoka, Shin‐ichi TakahashiAbstract:In this paper we present design methods for IIR filter banks. In the conventional works for IIR filter bank systems, the stable and causal systems which satisfy the condition of Perfect Reconstruction have not been well established yet. Most of these works do not satisfy both of these conditions (causality and Perfect Reconstruction). In this study, to design a two channel IIR filter bank system which satisfies the above two properties, we propose new design algorithms based on a Lagrange-multiplier method and Lagrange-Newton method. In this method the system achieves Perfect Reconstruction and has causality.
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Design of over sampled Perfect Reconstruction FIR filter banks
1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96, 1Co-Authors: Takayuki Nagai, Masaaki IkeharaAbstract:In this paper, we propose the design method for over sampled filter banks which satisfy the Perfect Reconstruction and linear phase properties. Moreover, we consider the design methods for both orthogonal and biorthogonal ones. We first derive the conditions of Perfect Reconstruction and linear phase for both biorthogonal and orthogonal filter banks. Then, we present the design methods for both cases. Finally some design examples are shown.
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ICASSP (3) - Cosine-modulated 2 dimensional FIR filter banks satisfying Perfect Reconstruction
Proceedings of ICASSP '94. IEEE International Conference on Acoustics Speech and Signal Processing, 1Co-Authors: Masaaki IkeharaAbstract:Considers the theory of cosine-modulated 2 dimensional (2-D) Perfect Reconstruction (PR) filter banks. First, a 2-D digital filter design with half passband, obtained by the sampling matrix, is discussed. Next, 2-D analysis filter banks are realized by cosine-modulating this prototype 2-D digital filter. It is shown that the modulation in the 2-D frequency plane is equivalent to the 1-D modulation. A necessary and sufficient condition for 2-D Perfect Reconstruction filter banks is derived. If the polyphase filter pairs of the prototype filter have a double-complement, the resulting 2-D filter bank satisfies the condition of Perfect Reconstruction. >
Andreas Antoniou - One of the best experts on this subject based on the ideXlab platform.
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ISCAS - Design of Perfect Reconstruction QMF banks by a null-space projection method
Proceedings of ISCAS'95 - International Symposium on Circuits and Systems, 1Co-Authors: Andreas AntoniouAbstract:A new method is proposed for the design of two-channel linear-phase Perfect Reconstruction QMF banks. The analysis lowpass filter is first designed by a conventional method, and then the synthesis lowpass filter is obtained by using a null-space projection approach. This method is then extended to the design of two-channel Perfect Reconstruction QMF banks with low Reconstruction delay, which are desirable in some applications. Two design examples are given to illustrate the proposed methods.
Henk J A M Heijmans - One of the best experts on this subject based on the ideXlab platform.
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Adaptive lifting schemes with Perfect Reconstruction
IEEE Transactions on Signal Processing, 2002Co-Authors: Gemma Piella, Henk J A M HeijmansAbstract:We propose a framework for constructing adaptive wavelet decompositions using the lifting scheme. A major requirement is that Perfect Reconstruction is possible without any overhead cost. We restrict ourselves to the update lifting stage. It is assumed that the update filter utilizes local gradient information to adapt itself to the signal in the sense that smaller gradients "evoke" stronger update filters. As a result, sharp transitions in a signal will not be smoothed to the same extent as regions that are more homogeneous. The approach taken in this paper differs from other adaptive schemes found in the literature in the sense that no bookkeeping is required in order to have Perfect Reconstruction.
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an adaptive update lifting scheme with Perfect Reconstruction
International Conference on Image Processing, 2001Co-Authors: Gemma Piella, Henk J A M HeijmansAbstract:The lifting scheme provides a general and flexible tool for the construction of wavelet decompositions and Perfect Reconstruction filter banks. We propose an adaptive version of this scheme which has the intriguing property that it allows Perfect Reconstruction without any overhead cost. We restrict ourselves to the update lifting step which affects the approximation signal only. The update lifting filter is assumed to depend pointwise on the norm of the associated gradient vector, in such a way that a large gradient induces a weak update filter. Thus, sharp transitions in a signal (eg, edges in an image) will not be smoothed to the same extent as regions which are more homogeneous.
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Adaptive lifting schemes with Perfect Reconstruction
2001Co-Authors: Henk J A M Heijmans, Gemma PiellaAbstract:textabstractIn this paper, we propose a framework for constructing adaptive wavelet decompositions using the lifting scheme. A major requirement is that Perfect Reconstruction is possible without any overhead cost. In this paper we restrict ourselves to the update lifting stage. It is assumed that the update filter utilises local gradient information to adapt itself to the signal in the sense that smaller gradients `evoke' stronger update filters. As a result, sharp transitions in a signal will not be smoothed to the same extent as regions which are more homogeneous. The approach taken in this paper differs from other adaptive schemes found in the literature in the sense that that no bookkeeping is required in order to have Perfect Reconstruction.
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Morphology-based Perfect Reconstruction filter banks
Proceedings of the IEEE-SP International Symposium on Time-Frequency and Time-Scale Analysis (Cat. No.98TH8380), 1998Co-Authors: Henk J A M Heijmans, J. GoustsiasAbstract:This paper discusses the construction of Perfect Reconstruction filter banks using morphological operators. Two concrete examples are given: (i) the morphological Haar wavelet, and (ii) a wavelet decomposition obtained from the lifting scheme which has the nice property that local maxima are preserved.
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ICIP (3) - An adaptive update lifting scheme with Perfect Reconstruction
Proceedings 2001 International Conference on Image Processing (Cat. No.01CH37205), 1Co-Authors: Gemma Piella, Henk J A M HeijmansAbstract:The lifting scheme provides a general and flexible tool for the construction of wavelet decompositions and Perfect Reconstruction filter banks. We propose an adaptive version of this scheme which has the intriguing property that it allows Perfect Reconstruction without any overhead cost. We restrict ourselves to the update lifting step which affects the approximation signal only. The update lifting filter is assumed to depend pointwise on the norm of the associated gradient vector, in such a way that a large gradient induces a weak update filter. Thus, sharp transitions in a signal (eg, edges in an image) will not be smoothed to the same extent as regions which are more homogeneous.
Jeanchristophe Pesquet - One of the best experts on this subject based on the ideXlab platform.
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M-band nonlinear subband decompositions with Perfect Reconstruction
IEEE transactions on image processing : a publication of the IEEE Signal Processing Society, 1998Co-Authors: F J Hampson, Jeanchristophe PesquetAbstract:We investigate nonlinear multirate filterbanks with maximal decimation and Perfect Reconstruction. Definitions of the desired properties of such structures are given for general nonlinear filterbanks. We then consider a triangular representation of linear filterbanks and see that it may be easily extended to the nonlinear case. Furthermore, general nonlinear filterbanks are presented, for which Perfect Reconstruction is either inherently guaranteed or ensured subject to an easily verified condition. Extensions to bidimensional filters are also discussed and an application for nonlinear multiresolution schemes to feature sieves is shown.
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a nonlinear subband decomposition with Perfect Reconstruction
International Conference on Acoustics Speech and Signal Processing, 1996Co-Authors: F J Hampson, Jeanchristophe PesquetAbstract:Multirate filter banks are of great interest for many applications in both signal and image processing. In particular, filter banks with critical subsampling and Perfect Reconstruction, have received special attention. Often such decompositions are restricted to linear analysis/synthesis filters possibly with some intermediate nonlinear treatment. We introduce a new structure which generates a variety of linear and nonlinear subband decompositions with critical subsampling. The structure is such that Perfect Reconstruction from the subband coefficients is guaranteed. As an example we consider applying it to image coding.
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ICASSP - A nonlinear subband decomposition with Perfect Reconstruction
1996 IEEE International Conference on Acoustics Speech and Signal Processing Conference Proceedings, 1Co-Authors: F J Hampson, Jeanchristophe PesquetAbstract:Multirate filter banks are of great interest for many applications in both signal and image processing. In particular, filter banks with critical subsampling and Perfect Reconstruction, have received special attention. Often such decompositions are restricted to linear analysis/synthesis filters possibly with some intermediate nonlinear treatment. We introduce a new structure which generates a variety of linear and nonlinear subband decompositions with critical subsampling. The structure is such that Perfect Reconstruction from the subband coefficients is guaranteed. As an example we consider applying it to image coding.
