Empirical evidence has demonstrated that learning-based image compression can outperform classical compression frameworks. This has led to the ongoing standardization of learned-based image codecs, namely Joint Photog...
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In the paper the idea of rational polynomial windows optimised towards low level of Fourier spectrum's sidelobes is presented. A relevant advantage of the polynomial windows family and their modifications is their...
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In the paper the idea of rational polynomial windows optimised towards low level of Fourier spectrum's sidelobes is presented. A relevant advantage of the polynomial windows family and their modifications is their ability to easily change their properties changing only the values of the polynomial coefficients. The obtained frequency characteristics demonstrate better properties of proposed rational windows than their standard polynomial equivalents requiring only the additional division operation. Such approach does not increase the computational complexity in significant way and the great advantage of polynomial windows which is their low computational complexity is preserved.
Optimal thresholds selection for multiwavelet denoising using multivariate shrinkage is considered. Unlike other risk estimators which are derived for a single threshold, a new risk estimator is proposed for each deco...
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Optimal thresholds selection for multiwavelet denoising using multivariate shrinkage is considered. Unlike other risk estimators which are derived for a single threshold, a new risk estimator is proposed for each decomposition level based on the principle of Stein's unbiased risk estimator.
This article describes the problems of use of spatial microphone arrays in sound source location. Questions concerning modelling of planar (2-D) and spatial (3-D) directional characteristics of microphone arrays are d...
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Air-gap data is important for the security of computer systems. The injection of the computer virus is limited but possible, however data communication channel is necessary for the transmission of stolen data. This pa...
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In parallel with rapid advances in computer technology, biomedical functional imaging is having an ever-increasing impact on healthcare. Functional imaging allows us to see dynamic processes quantitatively in the livi...
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In parallel with rapid advances in computer technology, biomedical functional imaging is having an ever-increasing impact on healthcare. Functional imaging allows us to see dynamic processes quantitatively in the living human body. However, as we need to deal with four-dimensional time-varying images, space requirements and computational complexity are extremely high. This makes information management, processing, and communication difficult. Using the minimum amount of data to represent the required information, developing fast algorithms to process the data, organizing the data in such a way as to facilitate information management, and extracting the maximum amount of useful information from the recorded data have become important research tasks in biomedical information technology. For the last ten years, the Biomedical and multimedia Information Technology (BMIT) Group and, recently, the Center for multimediasignalprocessing have conducted systematic studies on these topics. Some of the results relating to functional imaging data acquisition, compression, storage, management, processing, modeling, and simulation are briefly reported in this paper.
Remote sensing image classification is a popular yet challenging field. Many researchers have combined convolutional neural networks (CNNs) and Transformers for hyperspectral image (HSI) classification tasks. However,...
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The contourlet transform has emerged recently as an efficient directional multiresolution image decomposition. In order to enhance its distinguishing power for texture images, the high frequency band is split by half ...
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ISBN:
(纸本)0980326702
The contourlet transform has emerged recently as an efficient directional multiresolution image decomposition. In order to enhance its distinguishing power for texture images, the high frequency band is split by half and results in the multiscale directional filter bank (MDFB). However, this raises the computational complexity considerably because an extra set of scale and directional decomposition is required to perform on the full image size. In this paper, we develop a new framework for the MDFB, in which directional decomposition is performed prior to the scale decomposition in the first two scales. Experiments show that 30.6%-33.2% saving in computational time can be achieved. Meanwhile, it has the same flexibility in frequency partitioning and similar texture retrieval performance as the original algorithm of the MDFB.
Z-curve features are one of the popular features used in DNA sequence classification. Here, we studied the Z-curve features from a signalprocessing point of view. In particular, the Z-curve features are re-interprete...
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ISBN:
(纸本)0980326702
Z-curve features are one of the popular features used in DNA sequence classification. Here, we studied the Z-curve features from a signalprocessing point of view. In particular, the Z-curve features are re-interpreted through a spectral formulation. Our analysis showed that there are significant differences in the spectral interpretation between the Z-curve formulation and the FFT (Fast Fourier Transform) approach. From the spectral formulation of the Z-curve approach, we obtained three modified sequences that characterize different biological properties which are useful for coding region prediction. Spectral analysis on the modified sequences showed a much more prominent three-periodicity property in coding regions than using the FFT approach. Our experiments indicated that for long sequences, prominent peaks at 2II/3 are observed at coding regions. For short sequences, peaks can still be observed at coding regions. We also obtained good classification performance using the spectral features derived from the three modified sequences.
Nonlinear blind signal separation is an important but rather difficult problem. Any general nonlinear independent component analysis algorithm for such a problem should specify which solution it tries to find. Several...
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Nonlinear blind signal separation is an important but rather difficult problem. Any general nonlinear independent component analysis algorithm for such a problem should specify which solution it tries to find. Several recent neural networks for separating the post nonlinear blind mixtures are limited to the diagonal nonlinearity, where there is no cross-channel nonlinearity. In this paper, a new semi-parametric hybrid neural network is proposed to separate the post nonlinearly mixed blind signals where cross-channel disturbance is included. This hybrid network consists of two cascading modules, which are a neural nonlinear module for approximating the post nonlinearity and a linear module for separating the predicted linear blind mixtures. The nonlinear module is a semi-parametric expansion made up of two sub-networks, one of which is a linear model and the other of which is a three-layer perceptron. These two sub-networks together produce a "weak" nonlinear operator and can approach relatively strong nonlinearity by tuning parameters. A batch learning algorithm based on the entropy maximization and the gradient descent method is deduced. This model is successfully applied to a blind signal separation problem with two sources. Our simulation results indicate that this hybrid model can effectively approach the cross-channel post nonlinearity and achieve a good visual quality as well as a high signal-to-noise ratio in some cases.
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