In this paper, we present an adaptation of the spherical coder, which has been developed for wavelet transform, to wavelet packets. This coder uses local energy as a direct measure to differentiate the spatial informa...
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ISBN:
(纸本)9781424419982
In this paper, we present an adaptation of the spherical coder, which has been developed for wavelet transform, to wavelet packets. This coder uses local energy as a direct measure to differentiate the spatial informatin available in wavelet subbands and to decide how to allocate the available bitrate within each subband. As local energy becomes available at finer resolutions, Le. in smaller size windows, the coder automatically updates its decisions about how to spend the bitrate. We use a hierarchical set of variables to specify and code the local energy up to the highest resolution, i.e. the energy of individual wavelet coefficients. ne performance of the algorithm is improved by the use of optimal wavelet packet in terms of the energy distribution. ne resulting coder achieves over I dB coding gain, especially for textured images.
The purpose of this paper is to present a method of adaptation wavelet packet (WP) decomposition based on the auditory human perception criteria's applied to each ftame of the input signal. Several applications we...
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ISBN:
(纸本)9781424417230
The purpose of this paper is to present a method of adaptation wavelet packet (WP) decomposition based on the auditory human perception criteria's applied to each ftame of the input signal. Several applications were used this method, such as transform audio encoder and part of parametric encoderfor transient modeling. Both of these groups of application are very sensitive to the number of significant coefficients involved into the process. The main aim of the WP adaptation is to minimize the statistical and perceptual redundancy for further audio processing.
In this paper, the performance of several state-of-the-art watermark perceptual transparency metrics is evaluated through subjective assessment. Simulation results show that a metric based on S-CIELAB distortion maps ...
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ISBN:
(纸本)9789898111609
In this paper, the performance of several state-of-the-art watermark perceptual transparency metrics is evaluated through subjective assessment. Simulation results show that a metric based on S-CIELAB distortion maps proved to be better correlated to the subjective tests than other objective metrics available in the literature. The paper focus on image Adaptive Watermarking methods in the Discrete wavelet Transform Domain since they yield better results regarding robustness and transparency than other watermarking schemes.
In image denoising applications, noise is often correlated and the noise energy and correlation structure may even vary with the position in the image. Existing noise reduction and estimation methods are usually desig...
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ISBN:
(纸本)9781424417650
In image denoising applications, noise is often correlated and the noise energy and correlation structure may even vary with the position in the image. Existing noise reduction and estimation methods are usually designed for stationary white Gaussian noise and generally work less efficient in this case because of the noise model mismatch. In this paper, we propose an EM algorithm for the estimation of spatially variant (nonstationary) correlated image noise in the wavelet domain. In particular, we study additive white Gaussian noise filtered by a space-variant linear filter. This general noise model is applicable to a wide variety of practical situations, including noise in Computed Tomography (CT). Results demonstrate the effectiveness of the proposed solution and its robustness to signal structures.
This paper deals with the optimization of a new technique of image compression. After the wavelet transform of an image, blocks of coefficients are further linearly decomposed using a basis selected in a dictionary. T...
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ISBN:
(纸本)9781424417650
This paper deals with the optimization of a new technique of image compression. After the wavelet transform of an image, blocks of coefficients are further linearly decomposed using a basis selected in a dictionary. This dictionary is known by both the encoder and the decoder. This approach is a generalization of the bandelet transform. This paper investigates the problem of the best basis selection. On each block of wavelet coefficients, this selection is made by minimization of a Lagrangian rate-distortion criterion. Theoretical expressions of the optimal Lagrangian multiplier can be computed based on asymptotic hypotheses. A nearly exhaustive search of the optimal Lagrangian multiplier is done for the compression of high resolution satellite images. This numerical study validates the asymptotic theoretical expressions but as well provides a refined expression of the Lagrangian multiplier. At last, the compression results obtained using those different expressions are compared to the optimal compression results obtained with the exhaustive search.
作者：
Shyam, M.Anna Univ
Coll Engn Dept Elect & Commun Engn Madras 25 Tamil Nadu India
With the establishment of telemedicine clinics becoming the order of the day, identification of an ideal transmission scheme assumes critical importance. Large scale research on wavelet bases and their applicability i...
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ISBN:
(纸本)9781424419234
With the establishment of telemedicine clinics becoming the order of the day, identification of an ideal transmission scheme assumes critical importance. Large scale research on wavelet bases and their applicability in imageprocessing has given rise to a wide spectrum of denoising, enhancement and compression algorithms differing in quality and complexity. This paper aims at identifying the most ideal transmission standard for tele-medical applications, based on performance of different criteria.
The bilateral filter is a nonlinear filter that does spatial averaging without smoothing edges;it has shown to be an effective image denoising technique in addition to some other applications. There are two main contr...
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ISBN:
(纸本)9780819469946
The bilateral filter is a nonlinear filter that does spatial averaging without smoothing edges;it has shown to be an effective image denoising technique in addition to some other applications. There are two main contributions of this paper. First, we provide an empirical study of the optimal parameter selection for the bilateral filter in image denoising applications. Second, we present an extension of the bilateral filter: multi-resolution bilateral filter, where bilateral filtering is applied to low-frequency subbands of a signal decomposed using an orthogonal wavelet transform. Combined with wavelet thresholding, this new image denoising framework turns out to be very effective in eliminating noise in real noisy images. We provide experimental results with both simulated data and real data.
In this paper, an effective multiresolution image representation using the combination of 2D quincunx filter bank (FB) and directional wavelet transform (WT) is presented. The proposed method yields simple implementat...
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ISBN:
(纸本)9781424417650
In this paper, an effective multiresolution image representation using the combination of 2D quincunx filter bank (FB) and directional wavelet transform (WT) is presented. The proposed method yields simple implementation and low calculation costs compared to the other 1D and 2D FB combinations or adaptive directional WTs. Furthermore, it is a nonredundant transform and realizes quad-tree like multiresolution representation. In applications on nonlinear approximation and image coding, the proposed filter bank shows visual quality improvements and has higher PSNR.
Curvelets are a multiscale system with very high directional sensitivity. A new detection algorithm is herein described which operates on a curvelet decomposition of acoustic imagery. The algorithm detects the presenc...
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ISBN:
(纸本)9781424417650
Curvelets are a multiscale system with very high directional sensitivity. A new detection algorithm is herein described which operates on a curvelet decomposition of acoustic imagery. The algorithm detects the presence of cylindrical targets through a statistical mapping of curvelet coefficients. The coefficients are calculated as an inner product between image features and a curvelet basis element. The similarity in appearance between cylindrical targets and curvelet basis elements yield an accurate detection algorithm with a very low false alarm rate.
Watermarking is used for copyright protection using logo, image, stamp and text as a watermark. Recently, especially embedding binary image to color images has been worked alot and gave very promising results. In this...
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ISBN:
(纸本)9781424419982
Watermarking is used for copyright protection using logo, image, stamp and text as a watermark. Recently, especially embedding binary image to color images has been worked alot and gave very promising results. In this work we used text with small size characters and embed to color image as an image. We used Discrete wavelet Transform to embed partions of watermark to different frequency bants of cover image in two or more level decomposition, that is very useful in both copyright protection and information hiding. After common attacks we have got very promising results.
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