Transform-based image coders exploit the information packing ability of some mathematical transforms in order to reduce the number of significant transform coefficients needed to accurately represent an image. Large c...
详细信息
ISBN:
(纸本)0819422134
Transform-based image coders exploit the information packing ability of some mathematical transforms in order to reduce the number of significant transform coefficients needed to accurately represent an image. Large coefficients are often associated withthose regions where an image changes a lot, such as the boundaries between objects with differing visual characteristics. One way to reduce the number of significant transform coefficients is to segment an image into regions of similarity and then apply the transform to each region separately. We propose a novel image compression technique which first segments an image into arbitrary regions and then applies a region-adapted wavelet transform to each region.
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 ...
详细信息
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.
Suppose that (sigma) is a sigmoidal function which is the activation function of a neural network. Under certain assumptions on the derivatives of σ, we show that a simple linear combination of dilates and translates...
详细信息
In this paper, Malvar wavelets defined on a unit sphere are introduced. they are constructed by using a similar technique of constructing 2D Malvar wavelets, where one dimension (theta) is periodic on (0, 2(pi) ) and ...
详细信息
ISBN:
(纸本)0819422134
In this paper, Malvar wavelets defined on a unit sphere are introduced. they are constructed by using a similar technique of constructing 2D Malvar wavelets, where one dimension (theta) is periodic on (0, 2(pi) ) and the other dimension (phi) is not periodic on (0, (pi) ).
though wavelets have been used extensively for image coding, compression,and denoising, they are also gaining popularity in the geophysical sciences as an analysis tool. Capitalizing on the wavelet's relatively ti...
详细信息
ISBN:
(纸本)0819422134
though wavelets have been used extensively for image coding, compression,and denoising, they are also gaining popularity in the geophysical sciences as an analysis tool. Capitalizing on the wavelet's relatively tight localization in boththe time and frequency domains, the wavelet transform of a data field can yield significant information about the localized frequency content of the underlying process. As an analysis technique, though, standard wavelet transforms suffer from some of the real work constraints that data sets often impose. Primary among these is the fact that the data set is not typically supported on a standard rectangular grid. We investigate the application of a boundary-compensated wavelet transform supported on an arbitrarily-shaped region. applications to satellite-based altimetry of ocean basins are presented.
On the base of local criteria of processing quality, a class of local adaptive linear filters for image restoration and enhancement is introduced. the filters work in a running window in the domain of DFT of DCT and h...
详细信息
ISBN:
(纸本)0819422134
On the base of local criteria of processing quality, a class of local adaptive linear filters for image restoration and enhancement is introduced. the filters work in a running window in the domain of DFT of DCT and have O (size of the window) computational complexity thanks to recursive algorithms of running DFT and DCT. the filter design and the recursive computation of running DCT are outlined and filtering for edge preserved noise suppression, blind image restoration and enhancement is demonstrated.
the selection of most suitable mother wavelet function is still an open research problem in various signal and imageprocessingapplications. this paper presents a comparative study of different wavelet families (Daub...
详细信息
the selection of most suitable mother wavelet function is still an open research problem in various signal and imageprocessingapplications. this paper presents a comparative study of different wavelet families (Daubechies, Symlets, Coiflets, and Biorthogonal) for analysis of wrist motions from electromyography (EMG) signals. EMG signals are decomposed into three levels using discrete wavelet packet transform. From the decomposed EMG signals, root mean square (RMS) value, autoregressive (AR) model coefficients (4th order) and waveform length (WL) are extracted. Two data projection methods such as principal component analysis (PCA) and linear disciminant analysis (LDA) are used to reduce the dimensionality of the extracted features. Probabilistic neural network (PNN) and general regression neural network (GRNN) are employed to classify the different types of wrist motions, which gives a promising accuracy of above 99%. From the analysis, we inferred that 'Biorthogonal' and 'Coiflets' wavelet families are more suitable for accurate classification of EMG signals of different wrist motions. (C) 2012 Elsevier Ltd. All rights reserved.
this paper describes an approach for accomplishing sub- octave wavelet analysis and its discrete implementation for noise reduction and feature enhancement. Sub-octave wavelet transforms allow us to more closely chara...
详细信息
Blocking artifacts are the most objectionable drawback of block-based image and video coders. We describe a novel technique for removing blocking artifacts via multiscale edge processing. the new technique exploits th...
详细信息
ISBN:
(纸本)0819422134
Blocking artifacts are the most objectionable drawback of block-based image and video coders. We describe a novel technique for removing blocking artifacts via multiscale edge processing. the new technique exploits the advantages of an invertible multiscale edge representation from which the block edges can be easily identified and removed. By virtue of the multiscale edge processing one is able to deblock images effectively without blurring perceptually important features or introducing new artifacts. We present the deblocking algorithm with experimental results and a discussion.
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...
详细信息
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 withthe Haar multiresolution to illustrate several examples of oblique wavelet bases, and then use the Cohen-Daubechies-Plonka multiscaling function to construct several oblique multiwavelets.
暂无评论