Showing papers on "Quadrature mirror filter published in 1997"

Wavelets: A Mathematical Tool for Signal Analysis

Abstract: Foreword Preface Software Notation 1. What are wavelets? Waveform modeling and segmentation Time-frequency analysis Fast algorithms and filter banks 2. Time-Frequency Localization. Analog filters RMS bandwidths The short-time Fourier transform The integral wavelet transform Modeling the cochlea 3. Multiresolution Analysis. Signal spaces with finite RMS bandwidth Two simple mathematical representations Multiresolution analysis Cardinal splines 4. Orthonormal Wavelets. Orthogonal wavelet spaces Wavelets of Haar, Shannon, and Meyer Spline wavelets of Battle-Lemarie and Stromberg The Daubechies wavelets 5. Biorthogonal Wavelets. The need for duals Compactly supported spline wavelets The duality principle Total positivity and optimality of time-frequency windows 6. Algorithms. Signal representations Orthogonal decompositions and reconstructions Graphical display of signal representations Multidimensional wavelet transforms The need for boundary wavelets Spline functions on a bounded interval Boundary spline wavelets with arbitrary knots 7. Applications. Detection of singularities and feature extraction Data compression Numerical solutions of integral equations Summary and Notes References Subject Index.

Efficient polyphase quadrature digital tuner

Abstract: A polyphase quadrature digital tuner system which converts input signals to baseband inphase and quadrature signal components. The system includes a signal receiver which receives the input signals having a frequency centered around a predetermined carrier frequency. A signal processor continuously samples the input signals and multiplies selected portions of the input signals by a value of 1 or -1 to produce discrete sequences of N input samples, where N is an integer. An inphase signal channel includes a first set of N filters in a first filter stage each having respective filter coefficients, the first set of filters arranged to receive the discrete sequences, and a first signal summer which sums the outputs of the first set of N filters to produce the inphase signal component. A quadrature signal channel includes a second set of N filters in the first filter stage each having respective filter coefficients, the second set of filters arranged to receive the discrete sequences, and a second signal summer which sums the outputs of the second set of N filters to produce the quadrature signal component. The input samples are provided to the inphase and quadrature signal channels so that each filter of both channels receives one input sample of each sequence.

VLSI architectures for lattice structure based orthonormal discrete wavelet transforms

Abstract: We present efficient single-rate architectures for the one-dimensional orthonormal discrete wavelet transform (DWT). In the paper we make two contributions. First, we show that architectures that are based on the quadrature mirror filter (QMF) lattice structure require approximately half the number of multipliers and adders than corresponding direct-form structures. Second, we present techniques for mapping the 1-D orthonormal DWT to folded and digit-serial architectures which are based on the QMF lattice structure. For folded architectures, we discuss two techniques for mapping the QMF lattice structure to hardware. For digit-serial architectures, we show that any two-channel subband system can be implemented using digit-serial processing techniques by utilizing the polyphase decomposition. Using this result, we describe an orthonormal DWT architecture which uses the QMF lattice structure and digit-serial processing techniques. The proposed folded and digit-serial QMF lattice structures are attractive choices for implementations of the orthonormal DWT which require low area and low power dissipation.

Deriving texture feature set for content-based retrieval of satellite image database

Abstract: In this paper, the performance of similarity retrieval from satellite image databases by using different sets of spatial and transformed-based texture features is evaluated and compared. A benchmark consisting of 37 satellite image clips from various satellite instruments is devised for the experiments. We show that although the proposed feature set perform only slightly better with the Brodatz set, its performance is far superior for the satellite images. The result indicates that more than 25% of the benchmark patterns can be retrieved with more than 80% accuracy by using normalized Euclidean distance. In contrast, less than 10% of the patterns are retrieved with more than 80% accuracy by using transformed-based feature sets (such as those based on Gabor filter or quadrature mirror filter (QMF)).

Single sideband double quadrature modulator

Abstract: A method of and apparatus for effecting single sideband modulation which mixes and sums the quadrature and in-phase components of a baseband signal with the in-phase and quadrature components of an intermediate frequency (IF) signal to form in-phase and quadrature components of a sum signal having a frequency equal to the sum of the frequencies of the baseband and intermediate frequency signals and which mixes and sums the quadrature and in-phase components of an RF carrier signal with the in-phase and quadrature components of the sum signal to form a single-sideband signal.

Image content search by color and texture properties

Abstract: A new scheme for color and texture feature extraction for image content search is presented. We introduce a scheme using the two chrominance components for color information and a computationally efficient infinite impulse response (IIR) quadrature mirror filter bank (QMF) energy measure of the luminance component for texture information. The color and texture information is combined into one feature vector, and the components are balanced with respect to dimensionality. We illustrate the utility of our features with experiments in searching for a specific color texture in a large database of images. Several different sub-band decompositions are evaluated. Features extracted using a previously published Gabor filter bank are also evaluated against the proposed scheme. We conclude that the proposed scheme outperforms the Gabor features in both quality and complexity.

Stereoscopic video processing unit

Abstract: PROBLEM TO BE SOLVED: To obtain a more real stereoscopic image space by applying signal processing to image signals, so that a highest stereoscopic effect appears at a region in the vicinity of a noted point. SOLUTION: A left eye image signal and a right eye image signal are given to a display control section 107 via filter arithmetic sections 104, 105 respectively. Each filter coefficient of the filter arithmetic sections 104, 105 is set variable, depending on the coefficient from a filter coefficient generating section 112. The filter coefficient generating section 112 generates a filter coefficient for controlling the gain of the high frequency component at an arbitrary position of the left eye image signal and a right eye image signal in a time-base direction. A noted point parallax detection section 111 sets a region of an image to be noted and the filter generating section 112 generates a different filter coefficient for the setting area so that the regions other than the setting region. COPYRIGHT: (C)1999,JPO

Perfect reconstruction circular convolution filter banks and their application to the implementation of bandlimited discrete wavelet transforms

Abstract: This paper introduces a new filter bank structure called the perfect reconstruction circular convolution (PRCC) filter bank. These filter banks satisfy the perfect reconstruction properties, namely, the paraunitary properties in the discrete frequency domain. We further show how the PRCC analysis and synthesis filter banks are completely implemented in this domain and give a simple and a flexible method for the design of these filters. Finally, we use this filter bank structure for a frequency sampled implementation of the discrete wavelet transform based on orthogonal bandlimited scaling functions and wavelets.

Discrete Lagrangian method for optimizing the design of multiplierless QMF filter banks

Abstract: In this paper, we present a new discrete Lagrangian optimization method for designing multiplierless QMF (quadrature mirror filter) filter banks. In multiplierless QMF filter banks, filter coefficients are powers-of-two (PO2) where numbers are represented as sums or differences of powers of two (also cabled Canonical Signed Digit-CSD-representation), and multiplications can be carried out as additions, subtractions and shifting. We formulate the design problem as a nonlinear discrete constrained optimization problem, using the reconstruction error as the objective, and other performance metrics as constraints. One of the major advantages of this formulation is that it allows us to search for designs that improve over the best existing designs with respect to all performance metrics, rather than finding designs that trade one performance metric for another. We show that our design method can find designs that improve over Johnston's benchmark designs using a maximum of three to six ONE bits in each filter coefficient.

Lossless coding of still images with four channel prediction

Abstract: In this paper a new lossless coding of digital image data with a four channel filter bank (4ch FB) having optimized filter coefficients is proposed The method has an advantage of less restrictions on optimizing the filter coefficients compared to the cascade form of two channel filter banks (2ch FB) Simulation results are shown to confirm its effectiveness

QMF filter bank design by a new global optimization method

Abstract: We study various global optimization methods for designing QMF (quadrature mirror filter) filter banks. We formulate the design problem as a nonlinear constrained optimization problem, using the reconstruction error as the objective, and other performance metrics as constraints. This formulation allows us to search for designs that are improvements over the best existing designs. We present NOVEL, a global optimization method for solving nonlinear continuous constrained optimization problems. We show that NOVEL finds better designs with respect to simulated annealing and genetic algorithms in solving QMF benchmark design problems. We also show that relaxing the constraints on transition bandwidth and stopband energy leads to significant improvements in the other performance measures.

An efficient algorithm to design weighted minimax perfect reconstruction quadrature mirror filters

Abstract: An efficient algorithm is presented in this paper to design lattice-type perfect reconstruction quadrature mirror filters (PR-QMF). Our proposed iterative algorithm designs the lattice coefficients of the filter bank directly, with flexible control of the filters' stop-band ripple profiles. Typically, only a few iterations of our algorithm are needed to converge to an optimal solution in the weighted minimax sense. A procedure to obtain the lattice coefficients of PR-QMF banks yielding near linear phase filters is presented.

Multirate sub-band adaptive beamforming using different kernel QMF banks

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 ...

Design of causal IIR filter banks satisfying perfect reconstruction

Abstract: 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.

Digital filters associated with bivariate box spline wavelets

Abstract: Battle-Lemarie's wavelet has a nice generalization in a bivariate setting. This generalization is called bivariate box spline wavelets. The magnitude of the filters associated with the bivariate box spline wavelets is shown to converge to an ideal high-pass filter when the degree of the bivariate box spline functions increases to ∞. The passing and stopping bands of the ideal filter are dependent on the structure of the box spline function. Several possible ideal filters are shown. While these filters work for rectangularly sampled images, hexagonal box spline wavelets and filters are constructed to process hexagonally sampled images. The magnitude of the hexagonal filters converges to an ideal filter. Both convergences are shown to be exponentially fast. Finally, the computation and approximation of these filters are discussed.

Edge detection: conventional operators vis a vis wavelets

Abstract: :This work investigates a broad spectrum of conventional edge operators such as Sobel, Prewitt, Laplacian, Laplacian ofGaussian, and Roberts vis-a-vis upcoming multiresolution technique of Wavelets. The technique of image decomposition withwavelets involves filtering of the image using a Quadrature Mirror Filter pair (QMF) which brings out the details (usingcoefficients of highpass filter) and simultaneously smoothes the image (using coefficients of lowpass filter). Daubechies andHaar wavelet transforms have been used for the purpose of detecting edges. Haar wavelet has been found to be most attractivechoice for the purpose of edge detection with our methodology. A discussion and analysis of pros and cons of using waveletsagainst the conventional operators is presented in the paper.Keywords: Edge detection, Wavelets, Edge detection masks, Haar wavelet, Sobel, Prewitt, Laplacian, Laplacian of Gaussian,Roberts operator.INTRODUCTION:An edge is be defined as a sharp intensity transition between neighboring pixels in an image. Edges carry vital informationabout the image, as an object can be identified merely by its crude outline depicted by edges. The human visual system usesedges to extract information from an image. Edges are used for image segmentation .

1/M-octave-band filter banks and wavelets

Abstract: In this paper a new filter bank is presented. Its main features are exact 1/M-octave-band resolution, subband signals without aliasing and phase distortion, and perfect reconstruction. The system is based on oversampled complementary filter banks. Besides the usual dyadic sampling rate decimation techniques single-sideband modulation and demodulation are used. It is shown, that this filter bank constitutes a Discrete Wavelet Transform. Typical applications are the analysis and simulation of room acoustics in civil engineering and the signal decomposition in hearing aids.

Wavelets and Filter Banks

Abstract: We show that if an even length filter has the same length complementary filter in a generalized linear phase case, the complementary filter is unique, we find sufficient conditions for a unique existence of even length N complementary filter in a quadrature mirror filter bank, and we find all higher degree symmetric filters of length N + 4m which are complementary to a given symmetric filter of even length N .

Nonuniform modulated filter bank

Abstract: The design of modulated filter bank with nonuniform frequency allocations is considered. The nonuniform subband filters are formed by merging the subband filters of an uniform modulated filter bank. This simple merge preserved the spectral properties and the structure of the uniform modulated filter bank in the resulting nonuniform filter bank. The merge of subband filters of paraunitary modulated filter bank preserve the perfect reconstruction property. As a result, this seemingly idea gives rise to a simple design method for a large class of nonuniform modulate filter banks that are perfectly reconstruct. Design example of a nonuniform cosine modulated filter bank is derived. The performance of nonuniform cosine modulated filter bank under the presented framework is discussed.

Wideband speech coding on the basis of multirate filterbank trees

Abstract: For wideband speech coding in telecommunications a quadrature mirror filter (QMF) bank with recursive filters is used. Phase distortions are minimized by structural means and by compensation. A considerable data rate reduction is achieved based if psychoacoustical masking effects are exploited.

Design of near perfect reconstruction non-uniform filter banks

Abstract: Subband coding is widely used to compress speech, audio and video signals. In some applications, for example audio compression, a non-uniform splitting of the spectrum of a digital signal can be preferable to a uniform one. Some techniques that allow to implement a non-uniform width subband decomposition are here discussed, design methods based on the cosine-modulation of more than one prototype are described and some examples of filter bank design are given.

Hutlets: a biorthogonal wavelet family and their high-speed implementation with RNS multiplier-free perfect-reconstruction QMF

Abstract: The relationship between wavelets, Laplace pyramids and QMF are now well established. IN recent years biorthogonal wavelets have become of increased interest because, compared with orthogonal wavelets, they are symmetric and linear phase. In this paper the Hut function is used as a scaling function to construct a biorthogonal wavelet family, we call Hutlets. A realization with perfect reconstruction, multiplier-free quadrature mirror filters using RNS technic is proposed.THe approximation-filter is a CIC lowpass, the detail-filter is a CHPC highpass, and the reconstruction filters are IIRs. Exact pole-zero annihilation is guaranteed by implementing polynomial filters, over an integer ring, in the residue arithmetic system. Since CIC and CHPC designs rely on the exact annihilation of selected poles-zeros, a new facilitating technology is required which is fast, compact, and numerically exact. How this can be achieved is the thrust of this paper. An application of the Hutlets to pulse amplitude modulated signals is explained.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Die Hutlets - eine biorthogonale Wavelet-Familie: Effiziente Realisierung durch multipliziererfreie, perfekt rekonstruierende Quadratur Mirror Filter

Abstract: Wavelets provide a spectral, redundancy-free transformation of time signals which, compared with the Fourier transform, contain local information. In recent years biorthogonal wavelets have become of increased interest because, compared with orthogonal wavelets, they are symmetric and linear phase. In this papertheHut-functiondiscovered by W. Hilberg in 1971 is used as a scaling function (father wavelet) to construct a biorthogonal wavelet family, we call Hutlets. A realization with perfect reconstruction, multiplier-free quadrature mirror filters is proposed. An application of the Hutlets to pulse amplitude modulated radio control watch signals is explained.