Topic
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 published on a yearly basis
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TL;DR: It is shown, that maximal probability of signal detection is obtained in case of non-zero delay time of received signal, which depends on filter bandwidth.
Abstract: In this paper we consider wideband signal against noise receiving by quadrature correlation receiver with input band-pass filter. We obtain analytical expressions of detection characteristics. We analyzed dependences of correct receiving on delay time, signal-to-noise ratio and input filter bandwidth. It is shown, that maximal probability of signal detection is obtained in case of non-zero delay time of received signal, which depends on filter bandwidth.
01 Jun 2016
TL;DR: By applying the wavelet fourth moment as a mechanism for reconstruction of digital images in noisy environments, together with a reducing estimator of the mean square error, variance and standard deviation, as detector noise in the coefficients of the sub-matrix LH of wavelet decomposition results in simulations showing up to 31 dB for the PSNR.
Abstract: The discrete wavelet transform (DWT) is generally used in digital image processing to compress or filter images, its operation is based on a quadrature mirror filter that can analyze images in different frequency components. The DWT decomposes images into different sub-matrices representing the original image but in different frequencies analysis. The sub-images obtained is the representation of a low-pass filter and high-pass filter (LL), low-pass filter and high-pass filter (LH), high-pass filter and low-pass filter (HL), finally high-pass filter and high-pass filter (HH). In these sub-images the average noise is zero, but when an image is sent in a wireless channel changes the nature of the image by performing a shift of the mean value. The noise added to images can be eliminated by designing filters with high complexity and high costs, sometimes is diminished the rate of sending and receiving data sent due to the above conditions. Digital images tend to visually impaired decreasing its quality and sometimes tends to lose relevant information about this. By applying the wavelet fourth moment as a mechanism for reconstruction of digital images in noisy environments, together with a reducing estimator of the mean square error, variance and standard deviation, as detector noise in the coefficients of the sub-matrix LH of wavelet decomposition results in simulations showing up to 31 dB for the PSNR.
15 Aug 2016
TL;DR: In this article, improving of the group delay characteristic of the quadrature filter bank has been presented and a QMF bank with fifth order Transitional Butterworth-Elliptic filter as a prototype filter has been considered.
Abstract: In this paper improving of the group delay characteristic of the quadrature filter bank has been presented. As an example, QMF bank with fifth order Transitional Butterworth-Elliptic filter as a prototype filter, has been considered. Using this procedure, a QMF bank with almost perfect reconstruction has been obtained.
TL;DR: In this paper, two-dimensional nonseparable quincunx, rectangular and circular complementary filters are designed for an alias-free decimation and interpolation, which can be used to get scaling and wavelets functions.
Abstract: In this paper, the Two-Dimensional (2D) Complementary Filter (CF) Banks, a signal processing technique which can be used to get scaling and wavelets functions, are presented. The 2D multirate signal processing theory and complementary filters properties are the base of CF Banks, permitting us to consider different types of sampling and filters. Two-dimensional nonseparable quincunx, rectangular and circular complementary filters are designed for an alias free decimation and interpolation. When CF bank is implemented with quincunx sampling and filters, perfect reconstruction is achieved and although it is not reached in others cases, the analysis and synthesis are performed without aliasing. The CF banks are related with wavelet theory and procedures to get 2D scaling and bandpass wavelets functions from the L-level filter bank tree structure iteratively are shown. We illustrate scaling and wavelets functions convergence as the level of decomposition increases.
01 Nov 2006
TL;DR: A perfect reconstruction filter bank that generates N-band linear phase cosine modulated wavelets is proposed, which can generate smooth multiplicity N wavelets of arbitrary length and high stop band attenuation characteristics.
Abstract: A perfect reconstruction filter bank that generates N-band linear phase cosine modulated wavelets is proposed. This filter bank can generate smooth multiplicity N wavelets of arbitrary length and high stop band attenuation characteristics. N-band wavelets give more flexible time frequency tiling than the traditional octave band decomposition. Symmetry of basis functions helps accurate wavelet analysis than its nonsymmetrical counter parts. Major advantages like orthogonality, less implementation complexity due to the modulated structure, good filter quality, easy design even with regularity conditions, make this filter bank a good choice for image coding applications. Design examples and application to image compression are presented.