A multiscale vision model based on a pyramidal wavelet transform is described in the present paper. The pyramidal wavelet algorithm is modified in order to satisfy a correct sampling at each scale. Objects are defined...
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The objective of this paper is to investigate and provide insight into wavelet-based higher-order time-scale analysis, with an emphasis on the third-order statistic, the bispectrum. We also use a wavelet-based higher-...
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ISBN:
(纸本)0819422134
The objective of this paper is to investigate and provide insight into wavelet-based higher-order time-scale analysis, with an emphasis on the third-order statistic, the bispectrum. We also use a wavelet-based higher-order time- scale approach to detect and quantify intermittent phase- locking of first- and second-order components in laboratory generated random sea waves.
The accuracy of the wavelet approximation at resolution h equals 2-n to a smooth function f is limited by O(hn), where N is the number of vanishing moments of the mother wavelet (psi) . For any positive integer p, we ...
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ISBN:
(纸本)0819422134
The accuracy of the wavelet approximation at resolution h equals 2-n to a smooth function f is limited by O(hn), where N is the number of vanishing moments of the mother wavelet (psi) . For any positive integer p, we derive basis functions which allow us to recover a smooth f from its wavelet coefficients with accuracy O(hp). Related formulas for recovering derivatives of f are also given.
An image compression method based on wavelet transforms and the human visual system (HVS) is presented in this paper. In the proposed method, we emphasize on the issue of designing a quantizer for wavelet transform co...
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Orthogonal, semiorthogonal and biorthogonal wavelet bases are special cases of oblique multiwavelet bases. One of the advantage of oblique multiwavelets is the flexibility they provide for constructing bases with cert...
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ISBN:
(纸本)0819422134
Orthogonal, semiorthogonal and biorthogonal wavelet bases are special cases of oblique multiwavelet bases. One of the advantage of oblique multiwavelets is the flexibility they provide for constructing bases with certain desired shapes and/or properties. The decomposition of a signal in terms of oblique wavelet bases is still a perfect reconstruction filter bank. In this paper, we present several examples that show the similarity and differences between the oblique and other types of wavelet bases. We start with the Haar multiresolution to illustrate several examples of oblique wavelet bases, and then use the Cohen-Daubechies-Plonka multiscaling function to construct several oblique multiwavelets.
We investigate three approaches to VLSI implementation of wavelet filters. The direct form structure, the lattice form structure, and an algebraic structure are used to derive different architectures for wavelet filte...
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ISBN:
(纸本)0819422134
We investigate three approaches to VLSI implementation of wavelet filters. The direct form structure, the lattice form structure, and an algebraic structure are used to derive different architectures for wavelet filters. The algebraic structure exploits conjugacy properties in number fields. All approaches are explained in detail for the Daubechies 4- tab filters. We outline the philosophy of a design method for integrated circuits.
Multiwavelet transforms are a new class of wavelet transforms that use more than one prototype scaling function and wavelet in the multiresolution analysis/synthesis. The popular Geronimo-Hardin-Massopust multiwavelet...
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ISBN:
(纸本)0819422134
Multiwavelet transforms are a new class of wavelet transforms that use more than one prototype scaling function and wavelet in the multiresolution analysis/synthesis. The popular Geronimo-Hardin-Massopust multiwavelet basis functions have properties of compact support, orthogonality, and symmetry which cannot be obtained simultaneously in scalar wavelets. The performance of multiwavelets in still image compression is studied using vector quantization of multiwavelet subbands with a multiresolution codebook. The coding gain of multiwavelets is compared with that of other well-known wavelet families using performance measures such as unified coding gain. Implementation aspects of multiwavelet transforms such as pre-filtering/post-filtering and symmetric extension are also considered in the context of image compression.
Volume data such as those acquired by magnetic resonance imaging techniques can be compressed efficiently using the wavelet transform. wavelet compression methods need to retain both the value and the location of the ...
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ISBN:
(纸本)0819422134
Volume data such as those acquired by magnetic resonance imaging techniques can be compressed efficiently using the wavelet transform. wavelet compression methods need to retain both the value and the location of the significant coefficients. We present experimental results demonstrating the use of zerotree encoding methods in wavelet compression can enhance the ability to further compress volume data.
The performance of wavelet compression algorithms is generally judged solely as a function of the compression ratio and the vidual artifacts which are perceivable in the reconstructed image. The problem then becomes o...
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ISBN:
(纸本)0819422134
The performance of wavelet compression algorithms is generally judged solely as a function of the compression ratio and the vidual artifacts which are perceivable in the reconstructed image. The problem then becomes one of obtaining the best compression with fewest visible artifacts--a very subjective measure. Our wavelet compression algorithm uses an information theoretic analysis for the design of the compression maps. We have previously shown that maximizing the information for a given visual communication channel also maximizes the visual quality of the restored image. We utilize this to design quantization maps which maximize information for a given compression ratio. Hence we are able to design quantization maps which maximize the restorability of an image--i.e. the information content, the image quality, and the mean-square difference fidelity--for a given compression ratio.
The optics of satellite cameras as well as the satellite movement create a blurring effect to which is added a noise due to the electronics of the CCD captors. We introduce a deconvolution algorithm which is regulariz...
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ISBN:
(纸本)0819422134
The optics of satellite cameras as well as the satellite movement create a blurring effect to which is added a noise due to the electronics of the CCD captors. We introduce a deconvolution algorithm which is regularized with a hard thresholding technic, in a wavelet frame. The restoration procedure is fast and provides good metrical and perceptual results.
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