Fractographs are elevation maps of the fracture zone of some broken material. The technique employed to create these maps (confocal laser microscopy) often introduces noise composed of positive or negative 'spikes...
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ISBN:
(纸本)0819437646
Fractographs are elevation maps of the fracture zone of some broken material. The technique employed to create these maps (confocal laser microscopy) often introduces noise composed of positive or negative 'spikes' that must be removed before further analysis. Since the roughness of these maps contains useful information, it must be preserved. Consequently, conventional denoising techniques cannot be employed. We use continuous and discrete wavelet transforms of these images, and the properties of wavelet coefficients related to pointwise Holder regularity, to detect and remove the spikes.
Nowadays one of the most important issue linked to image transform is to take into account the singularities of a signal which is organized on more than one dimension. The best example is the wavelet transform extensi...
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ISBN:
(纸本)9780819469236
Nowadays one of the most important issue linked to image transform is to take into account the singularities of a signal which is organized on more than one dimension. The best example is the wavelet transform extension to two dimensional signal analysis. The drawback when one pass from a one dimensional signal process to a two dimensional signal process by simply using separability of wavelet transform is the over representation of irregularities in the wavelet transform domain. In order to decrease this drawback, second generation wavelet transform tries to take geometrical aspects of the image into account in the analysis of the image (one can find examples with bandelets, curvelets, ridgelets and others). 2 layers bandelets or first generation bandelets is among the first wavelet transform which uses the flow to enhance the efficiency of the process. The present proposition is mainly theoretical : we will propose now a pratical interpretation of this work in order to make a new implementation of the transform.
In this study, an efficient modified SPIHT algorithm and related architecture design is proposed for image compression. The proposed architecture is designed as a three stage pipeline structure. Different sized images...
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ISBN:
(纸本)9781509064946
In this study, an efficient modified SPIHT algorithm and related architecture design is proposed for image compression. The proposed architecture is designed as a three stage pipeline structure. Different sized images are compressed using the designed architecture for different bpp values. The computed PSNR values of the compressed images using the proposed algorithm and also the original algorithm is compared in order to test the performance of the proposed algorithm and architecture.
We treat nonparametric estimation of a regression function defined on a 'tensor product irregular grid,' that is, a grid constructed as the Cartesian product of two irregular one-dimensional grids. Our wavelet...
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ISBN:
(纸本)0819450804
We treat nonparametric estimation of a regression function defined on a 'tensor product irregular grid,' that is, a grid constructed as the Cartesian product of two irregular one-dimensional grids. Our wavelet-type estimator is based on a wavelet transform which is the tensor product of two one-dimensional design-adapted wavelet transforms. We propose a denoising scheme and show the performance of the resulting estimator through a simulation study.
wavelet transform technique is applied to the analysis of data collected in experiments on the characterization of nonlinear optical materials which may be in the form of liquid, thin film or crystal. Many characteriz...
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ISBN:
(纸本)0819422134
wavelet transform technique is applied to the analysis of data collected in experiments on the characterization of nonlinear optical materials which may be in the form of liquid, thin film or crystal. Many characterization techniques are based on nonlinear optical processes such as higher harmonic generation in which second harmonic or third harmonic signals may be generated by the nonlinear material. When the optical path length of the material is changed, the interference between bound and free waves forms a fringe pattern. Conventional Fourier transform techniques are not suitable for analyzing such fringes when they have a variable periodicity and a low signal-to-noise ratio. However, the wavelet transform method is best suited for such signals because it provides a better resolution in both space and frequency domains. In this study, optical properties of materials are extracted from these fringe patterns by decomposing them into coefficients which are inner products of the signal and a family of wavelets generated from a mother wavelet by dilation and shift operations.
Using wavelet networks, it is possible to capture the characteristics of non-linear dynamic systems in a multi- scale modeling strategy. Starting from the coarsest approximation we go step-wise to the finer scales. At...
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ISBN:
(纸本)0819422134
Using wavelet networks, it is possible to capture the characteristics of non-linear dynamic systems in a multi- scale modeling strategy. Starting from the coarsest approximation we go step-wise to the finer scales. At each step the error signal or the residue of the system is modeled. This procedure is repeated until the residual drops below some modeling error bound. The modeling is carried out using compactly supported biorthogonal wavelets. By choosing appropriate wavelet basis, it is possible to obtain a near optimal model.
The wavelet coefficients in 2-D discrete wavelet transform (DWT) subspaces have a peaky, heavy-tailed marginal distribution that can be well described by a Gaussian mixture statistical model. In this paper, a multisca...
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The wavelet coefficients in 2-D discrete wavelet transform (DWT) subspaces have a peaky, heavy-tailed marginal distribution that can be well described by a Gaussian mixture statistical model. In this paper, a multiscale implementation of fragile watermarks based on the Gaussian mixture model is presented. The presented new method can embed a message bit stream, such as personal signatures or copyright logos, into a host image. With the embedded message bits spreading over the whole image area, the new method can detect and localize any image tampering since it will inevitably destroy a certain message bits. Compared with some other fragile watermark techniques, the statistical model based method modifies only a very small amount of image data to embed watermarks and the modification is hardly perceived by human vision because it occurs at texture edges. Besides, the multiscale implementation of fragile watermarks based on the presented method can help distinguish some normal image operations such as compression from malicious attacks, which is meaningful in terms of semi-fragile watermarking applications.
We present a coder that yields good quality images at very high compression rates. It performs embedded coding and can carry out both lossy and lossless compression, properties which are suitable for progressive trans...
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ISBN:
(纸本)0819441929
We present a coder that yields good quality images at very high compression rates. It performs embedded coding and can carry out both lossy and lossless compression, properties which are suitable for progressive transmission;It is based on an integer to integer wavelet transform, and uses augmented zerotrees with a hybrid technique that incorporates bitplane coding as well.
This paper presents a stationary wavelet transform (SWT) method to de-noise the microarray images. It's well known that SWT is time invariant. Hence it makes particularly important in statistical signalprocessing...
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ISBN:
(纸本)0780376676
This paper presents a stationary wavelet transform (SWT) method to de-noise the microarray images. It's well known that SWT is time invariant. Hence it makes particularly important in statistical signalprocessingapplications, such as signal detection and de-noising. The testing result on sample microarray image has shown a clear and a better resolution image is obtained using this method.
This paper proposes an image watermarking algorithm that is robust to compression methods and noise addition. In the proposed method the wavelet transform of images is taken and watermarking is carried out in the wave...
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ISBN:
(纸本)0780383184
This paper proposes an image watermarking algorithm that is robust to compression methods and noise addition. In the proposed method the wavelet transform of images is taken and watermarking is carried out in the wavelet domain. In order to accomplish low visibility of the watermark within the image and enable robustness against attacks, watermarking of block averages is utilized. Experimental results show that the proposed method is considerably more robust against corrupting effects such as JPEG compression, addition of noise, cropping and scaling.
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