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.

New Approach to the Design of Low Complexity 9/7 Tap Wavelet Filters With Maximum Vanishing Moments

Abstract: In this paper, we present a novel approach for the design of 9/7 near-perfect-reconstruction wavelets that are efficient for image compression. These wavelets have maximum vanishing moments for both decomposition and reconstruction filters. Among the existing 9/7 tap wavelet filters, the Cohen–Daubechies–Feauveau (CDF) 9/7 are known to have the largest regularity. However, these wavelets have irrational coefficients thus requiring infinite precision implementation. Unlike state- of-art designs that compromise vanishing moments for attaining low-complexity coefficients, our algorithm ensures both. We start with a spline function of length 5 and select the remaining factors to obtain wavelets with rationalized coefficients. By proper choice of design parameters, it is possible to find very low complexity dyadic wavelets with compact support. We suggest a near half band criterion to attain a suitable combination of low-pass analysis and decomposition filters. The designed filter bank is found to give significant hardware advantage as compared with existing filter pairs. Moreover, these low-complexity wavelets have characteristics similar to standard (CDF 9/7) wavelets. The designed wavelets are tested for their suitability in applications such as image compression. Simulations results depict that the designed wavelets give comparable performances on most of the benchmark images. Subsequently, they can be used in applications that require fewer computations and lesser hardware.

2D four-channel perfect reconstruction filter bank realized with the 2D lattice filter structure

Abstract: A novel orthogonal 2D lattice structure is incorporated into the design of a nonseparable 2D four-channel perfect reconstruction filter bank. The proposed filter bank is obtained by using the polyphase decomposition technique which requires the design of an orthogonal 2D lattice filter. Due to constraint of perfect reconstruction, each stage of this lattice filter bank is simply parameterized by two coefficients. The perfect reconstruction property is satisfied regardless of the actual values of these parameters and of the number of the lattice stages. It is also shown that a separable 2D four-channel perfect reconstruction lattice filter bank can be constructed from the 1D lattice filter and that this is a special case of the proposed 2D lattice filter bank under certain conditions. The perfect reconstruction property of the proposed 2D lattice filter approach is verified by computer simulations.

Novel efficient approach for the design of equiripple quadrature mirror filters

Abstract: Quadrature mirror filters have been used extensively in subband coding of speech signals. The authors introduce a novel efficient approach for the design of equiripple quadrature mirror filters. The new approach is more efficient than the previously proposed design method in terms of computer time and memory requirement.

New Efficient Iterative Optimization Algorithm to Design the Two Channel QMF Bank

Abstract: This paper proposes an efficient method for the design of two channel quadrature mirror filter (QMF) bank. To achieve minimum value of reconstruction error near to perfect reconstruction, a linear optimization process has been proposed. Prototype low pass filter has been designed using Kaiser window function. The modified algorithm has been developed to optimize the reconstruction error using linear objective function through iteration method. The result obtained, show that the performance of the proposed algorithm is better than that of the already exists methods. Keywords—Filterbank, near perfect reconstruction, Kaiser window, QMF.

Design and evaluation of parallel quadrature mirror filters (PQMF)

Abstract: Quadrature mirror filters (QMF) have been proposed in /1/, and are now widely used in digital sub-band coding of speech. The standard approach to the QMF splitting/reconstruction of a signal is based on a tree arrangement of half-band QMF filters. In this paper, we show that, assuming a proper design, a parallel implementation of the QMF filter bank (PQMF) is much more efficient than the tree implementation. In the first part of the paper, the basic tree approach is briefly reviewed. Than the parallel filter bank structure is introduced, the equations for alias-free reconstruction are derived and solved. It is shown that the parallel approach can drastically be simplified by truncating the so computed impulse responses. The effects of this truncation have been experimentally evaluated and some rules of thumb have been established for optimum truncation order. An example of design is given to illustrate the proposed method.