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Design of Time-Frequency Optimal Three-Band Wavelet Filter Banks with Unit Sobolev Regularity Using Frequency Domain Sampling

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2016年第12期35卷 4501-4531页

作者： Bhati, Dinesh Sharma, Manish Pachori, Ram Bilas Nair, Sujath S. Gadre, Vikram M. Indian Inst Technol Dept Elect Engn Bombay Maharashtra India Indian Inst Technol Indore Discipline Elect Engn Indore Madhya Pradesh India

In this paper, we design three-band time-frequency-localized orthogonal wavelet filter banks having single vanishing moment. We propose new expressions to compute mean and variances in time and frequency from the samples of the Fourier transform of the asymmetric band-pass compactly supported wavelet functions. We determine discrete-time filter of length eight that generates the time-frequency optimal time-limited scaling and wavelet functions using cascade algorithm. Time-frequency product (TFP) of a function is defined as the product of its time variance and frequency variance. The TFP of the designed functions is close to 0.25 with unit Sobolev regularity. Three-band filter banks are designed by minimizing a weighted combination of TFPs of wavelets and scaling functions. Interestingly, empirical results show that time-frequency optimal, filter banks of length nine, designed with the proposed methodology, have unit Sobolev regularity, which is maximum achievable with single vanishing moment. Design examples for length six and length nine filter banks are given to demonstrate the effectiveness of the proposed design methodology.

关键词： Dyadic factorization Sobolev regularity Time-frequency localization Vanishing moment cascade algorithm Frequency domain sampling

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Superresolution Imaging Using Constrained Iterative Deconvolution 11

Superresolution Imaging Using Constrained Iterative Deconvol...

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IEEE 11th Conference on Industrial Electronics and Applications (ICIEA)

作者： Fu, Xiongjun Peng, Shuilian Qian, Shengqi Zhang, Chengyan Xie, Ming Li, Shuguang Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China Shanghai Aerosp Elect Technol Inst Shanghai 201109 Peoples R China

ISBN: (纸本)9781467386449

Constrained iterative deconvolution (CID) superresolution algorithm and its fast version, i.e., fast constrained-iterative deconvolution (FCID) are studied. These approaches are able to break through the aperture limiting to angular resolutions and can be applicable to two-dimensional imaging of non-coherent radars. However, FCID algorithm suffers fromd ivergence, which limits the improvement of angular resolutions. A cascade algorithm that FCID iterations alternate with CID iterations is developed in this paper. This algorithm significantly increases permissible FCID iterations, thus higher angular resolution of two-dimensional imaging is achieved with less computational burden.

关键词： CID FCID cascade algorithm higher angular resolution less computational burden

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Superresolution Imaging Using Constrained Iterative Deconvolution

Superresolution Imaging Using Constrained Iterative Deconvol...

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IEEE Conference on Industrial Electronics and Applications

作者： Xiongjun Fu Shuilian Peng Shengqi Qian Chengyan Zhang Ming Xie Shuguang Li School of Information and Electronics Beijing Institute of Technology Beijing 100081 China Shanghai Aerospace Electronic Technology Institute Shanghai 201109 China

ISBN: (纸本)9781467386456

Constrained iterative deconvolution (CID) super-resolution algorithm and its fast version, i.e., fast constrained-iterative deconvolution (FCID) are studied. These approaches are able to break through the aperture limiting to angular resolutions and can be applicable to two-dimensional imaging of non-coherent radars. However, FCID algorithm suffers fromd ivergence, which limits the improvement of angular resolutions. A cascade algorithm that FCID iterations alternate with CID iterations is developed in this paper. This algorithm significantly increases permissible FCID iterations, thus higher angular resolution of two-dimensional imaging is achieved with less computational burden.

关键词： CID FCID cascade algorithm Higher angular resolution Less computational burden

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Human colour skin detection in CMYK colour space

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IET IMAGE PROCESSING 2015年第9期9卷 751-757页

作者： Sawicki, Dariusz J. Miziolek, Weronika Warsaw Univ Technol Inst Theory Elect Engn Measurement & Informat Sys Warsaw Poland

Fast detection of skin colour in images is an important task for computer vision and image processing. In this study, a new thresholding method for detecting skin colour has been introduced. The proposed method uses CMYK colour space, which, although not popular in image processing, especially in skin detecting algorithm, turned out to be a good choice. Its properties seem the most appropriate for the task of skin colour detection. Some experiments have been worked out using Compaq Database - a large database of skin and non-skin photos. A comparison of the new method against well-known thresholding methods in RGB, YCbCr and HSV spaces were prepared. In this comparison, the proposed method in CMYK colour space wins. This good result was further improved using a simple cascade algorithm, where two spaces RGB and CMYK were used.

关键词： image colour analysis object detection skin computer vision image segmentation visual databases human colour skin detection CMYK colour space computer vision image processing thresholding method Compaq Database RGB space YCbCr space HSV space cascade algorithm

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Asymptotic expansions for linear homogeneous divide-and-conquer recurrences: Algebraic and analytic approaches collated

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THEORETICAL COMPUTER SCIENCE 2014年第C期548卷 25-53页

作者： Dumas, Philippe Inria Saclay SpecFun Team Palaiseau France

Among all sequences that satisfy a divide-and-conquer recurrence, those which are rational with respect to a numeration system are certainly the most basic and the most essential. Nevertheless, until recently this specific class of sequences has not been systematically studied from the asymptotic standpoint. We recall how a mechanical process designed by the author permits to compute their asymptotic expansions. The process is based on linear algebra, and involves computing Jordan normal forms, joint spectral radii, and solving dilation equations. The main contribution of the present article is the comparison between our algebraic method and the classical analytic number theory approach. Moreover, we develop new ways to compute the Fourier series of the periodic functions involved in the expansion. The article comes with an extended bibliography. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Divide-and-conquer recurrence Radix-rational sequence Spectral radius Dilation equation cascade algorithm Dirichlet series Fourier series

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Constructing Irislet: a New Wavelet Type which Matched for Iris Image Characteristics 2

Constructing Irislet: a New Wavelet Type which Matched for I...

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2nd International Conference on Information and Communication Technology (ICoICT)

作者： Isnanto, R. Rizal Satoto, Kodrat Iman Windasari, Ike Pertiwi Computer Engineering Department Diponegoro University Semarang Indonesia

ISBN: (纸本)9781479935802

Iris has a unique pattern that can be used in biometric recognition. To extract the features of the iris, it can be done based on the textural characteristics of the iris pattern. One method is a texture-based feature extraction using wavelet. To construct a wavelet type which matched for a signal, in this case two-dimensional signal from the iris image, the necessary steps are quite complex. In this research, all stages of wavelet design are carried out, beginning from iris image data acquisition up to the finding of the new wavelet, which will then be referred to as irislet. There are 19 (nineteen) steps in the design of this wavelet. To do all the stages, several basic concepts are required: convolution, circular Hough transform, conversion into unwrapped polar image form, determining the profile of the 1-D line images, signal averaging, concept of Daubechies wavelet basis, calculating signal energy, least squares method, how to construct scaling and wavelet functions, as well as the cascade algorithm. The test results showed that the recognition implementation irislet shows recognition rate is 100% correct.

关键词： irislet scaling function wavelet function least squares method cascade algorithm

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Convergence and error estimate of cascade algorithms with infinitely supported masks in L_p(R^s)

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Science China Mathematics 2012年第3期55卷 577-592页

作者： YANG JianBin LI Song Department of Mathematics College of Sciences Hohai University Nanjing 210098 China Department of Mathematics College of Sciences Zhejiang University Hangzhou 310027 China

The cascade algorithm plays an important role in computer graphics and wavelet *** this paper,we first investigate the convergence of cascade algorithms associated with a polynomially decaying mask and a general dilation matrix in L p (R s) (1 p ∞) spaces,and then we give an error estimate of the cascade algorithms associated with truncated *** is proved that under some appropriate conditions if the cascade algorithm associated with a polynomially decaying mask converges in the L p-norm,then the cascade algorithms associated with the truncated masks also converge in the L ***,the error between the two resulting limit functions is estimated in terms of the masks.

关键词： cascade algorithm polynomially decaying masks error estimate

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Generalized Pseudo-Butterworth Refinable Functions

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JOURNAL OF FOURIER ANALYSIS AND APPLICATIONS 2013年第2期19卷 296-311页

作者： Luo, Zhongxuan Qi, Wanfeng Zhou, Mengmeng Zhang, Jielin Dalian Univ Technol Sch Math Sci Dalian Liaoning Peoples R China

In this paper we propose the generalized pseudo-Butterworth refinable functions which involve pseudo-splines of type I and II, Butterworth refinable functions, pseudo-Butterworth refinable functions, and almost all symmetric and causal fractional B-splines. Furthermore, the convergence of cascade algorithms associated with the new masks is proved, and Riesz wavelet bases in L (2)(a"e) corresponding to the parameters are constructed. The regularity of the generalized pseudo-Butterworth refinable functions is also analyzed by Fourier analysis.

关键词： Pseudo-Butterworth masks cascade algorithm Riesz wavelet basis Sobolev exponent

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Some Sufficient Conditions for Convergent Multivariate Subdivision Schemes with Nonnegative Finite Masks

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1411-1420页

作者： Min WU Jia Li ZHOU Department of Mathematics Zhejiang University of Science and Technology Department of Mathematics Zhejiang University of Technology

It is well known that the convergence of multivariate subdivision schemes with finite masks can be characterized via joint spectral radius. For nonnegative masks, we will present in this paper some computable simply s... 详细信息

关键词： cascade algorithm dilation equation joint spectral radius mask subdivision scheme

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The spline filter: A regularization approach for the Gaussian filter

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PRECISION ENGINEERING-JOURNAL OF THE INTERNATIONAL SOCIETIES FOR PRECISION ENGINEERING AND NANOTECHNOLOGY 2012年第4期36卷 586-592页

作者： Zhang, Hao Yuan, Yibao Piao, Weiying Nanjing Forestry Univ Coll Mech & Elect Engn Nanjing Jiangsu Peoples R China Harbin Inst Technol Sch Elect Engn & Automat Harbin 150006 Peoples R China

The Gaussian filter described in the ISO 11562 standard has become the most widely used filtering technique in surface metrology. However, this filter is always plagued by the large distortions called end effects at the boundaries of the filtered result. In order to alleviate the end effects, the spline filter based on natural cubic splines is incorporated into ISO standard as a substitute. So there exist two kinds of linear profile filters with different transmission characteristics which also lead to different mean lines for the assessment of the same surface. A new spline algorithm for determining the Gaussian filtered mean line is deduced using the central limit theorem. The filter uses the cascade method of the approximating spline filter, and therefore can approximate the transmission characteristic of the Gaussian filter with high accuracy. It is proved that the transmission characteristic relative deviation of the cascade approximating spline filter from the Gaussian filter is only 0.3% when the cascade order approaches infinity. With this theorem, it is easy to achieve the unification of the international standard ISO 16610-21 and ISO 16610-22. (C) 2012 Elsevier Inc. All rights reserved.

关键词： Approximating spline filter cascade algorithm Gaussian filter Surface metrology

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