Perfect Reconstruction QMF Banks Research Articles

Design of M-channel pseudo near perfect reconstruction QMF bank for image compression

Design of M-channel pseudo near perfect reconstruction QMF bank for image compression

Efficient design method of cosine-modulated QMF banks satisfying PR property

In this paper the design problem of perfect-reconstruction cosine-modulated QMF banks has been formulated as a quadratic-constrained least-squares (QCLS) minimization problem in which all constrained matrices of the QCLS optimization problem are symmetric and positive definite. A cost function which is a convex function of desired prototype filter coefficients is constructed so that this kind of QCLS optimization problems can be efficiently solved. So a global minimizer of this problem can be easily obtained. Results of two design examples are presented to support the derivations and analyses.

An efficient design method of cosine-modulated QMF banks satisfying PR property

In this paper the design problem of perfect-reconstruction cosine-modulated QMF banks has been formulated as a quadratic-constrained least-squares (QCLS) minimization problem in which all constrained matrices of the QCLS optimization problem are symmetric and positive definite. A cost function which is a convex function of desired prototype filter coefficients is constructed so that this kind of QCLS optimization problems can be efficiently solved. So a global minimizer of this problem can be easily obtained. Results of two design examples are presented to support the derivations and analyses.

A realizable paraunitary perfect reconstruction QMF bank based on IIR filters

In this paper, we address the problem of realizing a paraunitary perfect reconstruction quadrature mirror filter bank based on IIR filters. The bank is devoted to the analysis of transient phenomena, in particular of seismic traces from which the information of the arrival times of the incoming phases must be extracted. We have shown recently (Lo Presti and Olmo, To be submitted) that this task requires the realization of highly selective filter banks, which makes it necessary to resort to IIR solutions. The details of the implementation of such a filter bank are addressed, with particular emphasis on the border effects which arise due to the presence of noncausal filters. Solutions which avoid both the signal scattering and the initial condition errors are proposed for the particular class of signals at hand, namely vanishing ones. The addition of zeros at the head and tail of the sequence can effectively combat distorsion in the recovered signal, and at the same time does not affect the coefficients of the decomposition. A signal support enlargement can be tolerated for the application at hand, which is focused on the data analysis. Rules are given in order to evaluate the number of zeros to be added, as a function of the employed filters. The results in terms of the reconstruction error are rather satisfactory for the considered class of signals.

A simple design method of perfect reconstruction QMF banks

The problem of the nonlinear programming technique is that the quality of the obtained quadrature mirror filters depends on the initial solution because there are many local optimums. This paper presents a simple and efficient design method of linear phase PR QMF systems for M = 2. Nonlinear programming techniques are not used. The obtained filters are guaranteed to have good quality. One can specify the cutoff frequency of the low pass filter arbitrarily.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Perfect reconstruction QMF banks for two-dimensional applications

A theory is outlined whereby it is possible to design a M \times N channel two-dimensional quadrature mirror filter bank which has perfect reconstruction property. Such a property ensures freedom from aliasing, amplitude distortion, and phase distortion. The method is based on a simple property of certain transfer matrices, namely the losslessness property.