Integer based-matrix algorithms for discrete Haar transform (DHT) and discrete wavelet transform (DWT) are proposed with relation to the multiresolution representation (MRR). A recursive wavelet transform technique is...
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ISBN:
(纸本)0819425915
Integer based-matrix algorithms for discrete Haar transform (DHT) and discrete wavelet transform (DWT) are proposed with relation to the multiresolution representation (MRR). A recursive wavelet transform technique is used with a view to demonstrating simply lossy reconstructed images in contrast to an original image under the specified resolution size. A visual effect of reconstructed images with differnt appearance and image quality, caused by modifying or throwing away a part of the 2-D HT or WT coefficients, is discussed with a measure of quantitative evaluation such as similarity and/or modified similarity, and fidelity RMSE and/or PSNR.
The denoising of a natural image corrupted by Gaussian noise is a long established problem in signal or imageprocessing Even though much work has been done in the field of wavelet thresholding, most of it was focused...
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ISBN:
(纸本)0769530508
The denoising of a natural image corrupted by Gaussian noise is a long established problem in signal or imageprocessing Even though much work has been done in the field of wavelet thresholding, most of it was focused on statistical modeling of wavelet coefficients and the optimal choice of thresholds. This paper describes a new method for suppression of noise in image by fusing the wavelet Denoising technique with optimized thresholding function, improving the denoised results significantly. Simulated noise images are used to evaluate the denoising performance of proposed algorithm along with another wavelet-based denoising algorithm. Experimental result shows that the proposed denoising method outperforms standard wavelet denoising techniques in terms of the PSNR and the preservation of edge information. We have compared this with various denoising methods like wiener filter Visit Shrink, Oracle Shrink and Bayes Shrink.
Recent years have seen the development of signal denoising algorithms based on wavelet transform. It has been shown that thresholding the wavelet coefficients of a noisy signal allows to restore the smoothness of the ...
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ISBN:
(纸本)0780370414
Recent years have seen the development of signal denoising algorithms based on wavelet transform. It has been shown that thresholding the wavelet coefficients of a noisy signal allows to restore the smoothness of the original signal. However, wavelet denoising suffers of a main drawback : around discontinuities the reconstructed signal is smoothed, exhibiting pseudo-Gibbs phenomenon. We consider the problem of denoising piecewise smooth signals with sharp discontinuities. We propose to apply a traditional wavelet denoising method and to restore the denoised signal using a total variation minimization approach. This second step allows to remove the Gibbs phenomena and therefore to restore sharp discontinuities, while the other structures are preserved. The main innovation of our algorithm is to constrain the total variation minimization by the knowledge of the remaining wavelet coefficients. In this way, we make sure that the restoration process does not deteriorate the information that has been considered as significant in the denoising step. With this approach we substantially improve the performance of classical wavelet denoising algorithms, both in terms of SNR and in terms of visual artifacts.
The method in which the wavelet transform and fractal theories are applied to detect chaotic signals with the additive observed noises is presented in this paper. Smoothing operator is derived from wavelet transform a...
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ISBN:
(纸本)0819422134
The method in which the wavelet transform and fractal theories are applied to detect chaotic signals with the additive observed noises is presented in this paper. Smoothing operator is derived from wavelet transform and used to process the chaotic time series. According to its character of no-scale interval in certain scales, a detected example of the noisy chaotic behavior produced by a Lorenz attractor is provided by using the improved G-P algorithm to calculate its fractal dimension. The results shows that the method introduced here expresses a good ability to detect chaos.
In a multimedia framework, digital image sequences (videos) are by far the most demanding as far as storage, search, browsing and retrieval requirements are concerned. In order to reduce the computational burden assoc...
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ISBN:
(纸本)0819432997
In a multimedia framework, digital image sequences (videos) are by far the most demanding as far as storage, search, browsing and retrieval requirements are concerned. In order to reduce the computational burden associated to video browsing and retrieval, a video sequence is usually decomposed into several scenes (shots) and each of them is characterized by means of some key frames. The proper selection of these key frames, i.e. the most representative frames in the scene, is of paramount importance for computational efficiency. In this contribution a novel key frame extraction technique based on the wavelet analysis is presented. Experimental results show the capability of the proposed algorithm to select key frames properly summarizing the shot.
We propose two algorithms based on the embedded zerotree wavelet approach to encode multispectral images. The Said-Pearlman algorithm is adapted to the case of multispectral images by considering spectral vectors of p...
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ISBN:
(纸本)0818681837
We propose two algorithms based on the embedded zerotree wavelet approach to encode multispectral images. The Said-Pearlman algorithm is adapted to the case of multispectral images by considering spectral vectors of pixels rather than isolated pixels and by carrying out either VQ or KLT on these vectors, set as to take into account interband dependencies. Numerical experiments on a sample multispectral image show avery good performance for both algorithms.
This paper presents an application of 2D continuous wavelet transform (WT) to texture analysis. A complete set of wavelets is defined from an isotropic mother wavelet called the Mexican hat, allowing the decomposition...
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To improve lattice vector quantization (LVQ) performance in image compression applications, we propose to design a new code book shape adapted thresholding. As for scalar dead zone quantizer, the goal here is to remov...
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ISBN:
(纸本)0780376226
To improve lattice vector quantization (LVQ) performance in image compression applications, we propose to design a new code book shape adapted thresholding. As for scalar dead zone quantizer, the goal here is to remove non significant data, but in our case the n-dimensional dead zone permits to exploit characteristics of source vectors (i.e. blocks of wavelet coefficients). A theoretical rate model is defined for this new truncation shape. It permits to tune the dead zone parameters in order to reach a minimum of distortion of the quantized source at a given rate, and thus to overperform classical LVQ.
The cardiosynchronous signal obtained through Radio Frequency Impedance Interrogation (RFii) is a non-invasive method for monitoring hemodynamics with potential applications in combat triage and biometric identificati...
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ISBN:
(纸本)9781467325332;9781467325349
The cardiosynchronous signal obtained through Radio Frequency Impedance Interrogation (RFii) is a non-invasive method for monitoring hemodynamics with potential applications in combat triage and biometric identification. The RFiisignal is periodic in nature dominated by the heart beat cycle. The first step in both of these applications is to segment the signal by identifying a fiducial point in each heart beat cycle. A continuous wavelet transform was utilized to locate the fiducial points with high temporal resolution. Cepstral Analysis was used to estimate the average heart rate to focus on the appropriate portion of the time-frequency spectrum. Robust heartbeats from RFiisignals collected from four subjects were segmented using this method.
A text watermark algorithm using wavelet transform and error-correcting code for color image is presented in this paper. First, We decompose the blue channel of original color image to three levels using Daubechies...
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ISBN:
(纸本)0780374886
A text watermark algorithm using wavelet transform and error-correcting code for color image is presented in this paper. First, We decompose the blue channel of original color image to three levels using Daubechies' wavelets, which are well suited to deal with general-purpose images. Then the error-correcting encoded. text watermark is embedded by modifying the middle-frequency range of wavelet coefficients under the indicating of wavelet Coefficient Relation Matrix (WCRM), which is obtained by comparing coefficients of each resolution layer. The recovering of watermark does not require original image. Experimental results show that the algorithm is robust to some imageprocessing operations and JPEG lossy compression.
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