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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
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Proceedings ArticleDOI
27 Jun 2012
TL;DR: The new proposed Gauss-Hermite quadrature information filter is more flexible to use and can achieve higher level estimation accuracy than the extended information filter and the unscented information filter, and is thus computationally more efficient.
Abstract: In this paper, a sparse Gauss-Hermite quadrature information filter (SGHQIF) is proposed for multiple sensor estimation. The new proposed information filter is more flexible to use and can achieve higher level estimation accuracy than the extended information filter and the unscented information filter. In addition, the new filter maintains the close performance to the conventional Gauss-Hermite information filter with significantly fewer quadrature points and is thus computationally more efficient. The performance of these information filters is compared via a target tracking problem and the SGHQIF is shown to be the best one balancing the estimation accuracy with computational efficiency.

17 citations

Journal ArticleDOI
TL;DR: In this paper, a linear-phase quadrature mirror filter (QMF) with powers-of-two coefficients was designed based on a recently developed weighted least-squares (WLS) algorithm.
Abstract: This paper considers the design of linear-phase quadrature mirror filters (QMF's) with powers-of-two coefficients. A design method based on a recently developed weighted least-squares (WLS) algorithm is presented. First, we design QMF's with continuous coefficients using the WLS algorithm. This design process provides two favorable design results that the prototype analysis filter has quasi-equiripple stopband response and the resulting QMF bank shows quasi-equiripple reconstruction error behavior. To avoid the effect of nonuniformly distributed coefficient grid due to discretization of the filter coefficients, a procedure is then performed for obtaining an appropriate filter gain factor. Finally, utilizing the resulting error weighting function obtained by the WLS algorithm, we propose an efficient discrete optimization process to obtain a discrete solution in the minimax optimal sense. Design examples demonstrating the effectiveness of the proposed method are included. >

17 citations

Journal ArticleDOI
TL;DR: A new discrete Lagrangian method for designing multiplierless quadrature mirror filter banks that can find designs that improve over Johnston's benchmark designs using a maximum of three to six ONE bits in each filter coefficient instead of using floating-point representations.
Abstract: In this paper, we present a new discrete Lagrangian method for designing multiplierless quadrature mirror filter banks. The filter coefficients in these filter banks are in powers-of-two, where numbers are represented as sums or differences of powers of two (also called canonical signed digit representation), and multiplications are carried out as additions, subtractions, and shifts. We formulate the design problem as a nonlinear discrete constrained optimization problem, using reconstruction error as the objective, and stopband and passband energies, stopband and passband ripples, and transition bandwidth as constraints. Using the performance of the best existing designs as constraints, we search for designs that improve over the best existing designs with respect to all the performance metrics. We propose a new discrete Lagrangian method for finding good designs and study methods to improve the convergence speed of Lagrangian methods without affecting their solution quality. This is done by adjusting dynamically the relative weights between the objective and the Lagrangian part. We show that our method can find designs that improve over Johnston's benchmark designs using a maximum of three to six ONE bits in each filter coefficient instead of using floating-point representations. Our approach is general and is applicable to the design of other types of multiplierless filter banks.

17 citations

Proceedings ArticleDOI
16 Sep 1994
TL;DR: Biorthogonal wavelets or filterbanks are shown to be superior in coding gain performance than orthogonal ones for logarithmic subband decompositions as discussed by the authors, which is shown for maximally regular biorhogonal and orthogonality filters, as well as filters designed to optimize the subband coding grain.
Abstract: Biorthogonal wavelets or filterbanks are shown to be superior in coding gain performance than orthogonal ones for logarithmic subband decompositions (limited to iterative decomposition of the downsampled output of the analysis low-pass filter). As a consequence, for logarithmic decompositions, the optimal filter is not an ideal filter. This is shown for maximally regular biorthogonal and orthogonal filters, as well as filters designed to optimize the subband coding grain.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

17 citations

Journal ArticleDOI
TL;DR: Given a sequence of different exposures, the Quadrature Mirror Filter based subband architecture is first employed to decompose the original sequence into different frequency subbands, and the importance weight maps according to the image appearance measurements, such as exposure, contrast, and saturation are computed.
Abstract: In this paper, we present a novel detail-preserving fusion approach from multiple exposure images using subband architecture. Given a sequence of different exposures, the Quadrature Mirror Filter (QMF) based subband architecture is first employed to decompose the original sequence into different frequency subbands. After that, we compute the importance weight maps according to the image appearance measurements, such as exposure, contrast, and saturation. In order to preserve the details of the subband signals, we compute the gain control maps and improve these subbands. Finally, the coefficients of subbands are blended into a high-quality detail-preserving fusion image. Experimental results demonstrate that the proposed approach successfully creates a visually pleasing exposure fusion image.

17 citations

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