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AN APPLIED RESEARCH ON APPROACH OF DYADIC WAVELET TRANSFORM FOR REMOTE SENSING IMAGE EDGE DETECTION 被引量:1
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作者 Fu Wei Xing Guangzhong +2 位作者 Hou Lantian Qin Qiming Wang Wenjun 《Journal of Electronics(China)》 2006年第4期535-538,共4页
In the edge detection of Remote Sensing (RS) image, the useful detail losing and the spurious edge often appear. To solve the problem, the authors uses the dyadic wavelet to detect the edge of surface features by comb... In the edge detection of Remote Sensing (RS) image, the useful detail losing and the spurious edge often appear. To solve the problem, the authors uses the dyadic wavelet to detect the edge of surface features by combining the edge detecting with the multi-resolution analyzing of the wavelet transform. Via the dyadic wavelet decomposing, the RS image of a certain appropriate scale is obtained, and the edge data of the plane and the upright directions are respectively figured out, then the gradient vector module of the surface features is worked out. By tracing them, the authors get the edge data of the object, therefore build the RS image which obtains the checked edge. This method can depress the effect of noise and examine exactly the edge data of the object by rule and line. With an experiment of an RS image which obtains an airport, the authors certificate the feasibility of the application of dyadic wavelet in the object edge detection. 展开更多
关键词 dyadic wavelet transform Edge detection and tracking of Remote Sensing (RS) Object recognition
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COMPUTATION OF CONTINUOUS WAVELET TRANSFORM AT DYADIC SCALES BY SUBDIVISION SCHEME
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作者 S.Riemenschneider S.Xu 《Analysis in Theory and Applications》 1996年第4期26-45,共20页
A new algorithm to compute continuous wavelet transforms at dyadic scales is proposed here. Our approach has a similar implementation with the standard algorithme a trous and can coincide with it in the one dimensiona... A new algorithm to compute continuous wavelet transforms at dyadic scales is proposed here. Our approach has a similar implementation with the standard algorithme a trous and can coincide with it in the one dimensional lower order spline case.Our algorithm can have arbitrary order of approximation and is applicable to the multidimensional case.We present this algorithm in a general case with emphasis on splines anti quast in terpolations.Numerical examples are included to justify our theorerical discussion. 展开更多
关键词 TH COMPUTATION OF CONTINUOUS wavelet TRANSFORM AT dyadic SCALES BY SUBDIVISION SCHEME CWT Morlet
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A New Pitch Detection Algorithm Based on Wavelet Transform 被引量:1
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作者 宋兵 顾传青 张建军 《Journal of Shanghai University(English Edition)》 CAS 2005年第4期309-313,共5页
In this paper, a new event detection pitch detector based on the dyadic wavelet transform was constrcted by selecting an optimal scale. The proposed pitch detector is accurate, robust to noise and computationally simp... In this paper, a new event detection pitch detector based on the dyadic wavelet transform was constrcted by selecting an optimal scale. The proposed pitch detector is accurate, robust to noise and computationally simple. Experiments show the superior performance of this event-based pitch detector in comparison with previous event-based pitch detector and classical pitch detectors that use the autocorrelation and the cepsmun methods to estimate the pitch period. 展开更多
关键词 glottal closure instants dyadic wavelet transform pitch detection optimal scale.
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Feature Extraction and Classification of Echo Signal of Ground Penetrating Radar 被引量:5
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作者 ZHOU Hui-lin TIAN Mao CHEN Xiao-li 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第6期1009-1012,共4页
Automatic feature extraction and classification algorithm of echo signal of ground penetrating radar is presented. Dyadic wavelet transform and the average energy of the wavelet coefficients are applied in this paper ... Automatic feature extraction and classification algorithm of echo signal of ground penetrating radar is presented. Dyadic wavelet transform and the average energy of the wavelet coefficients are applied in this paper to decompose and extract feature of the echo signal. Then, the extracted feature vector is fed up to a feed forward muhi layer perceptron classifier. Experimental results based on the measured GPR, echo signals obtained from the Mei shan railway are presented. 展开更多
关键词 ground penetrating radar nonstationary signal dyadic wavelet transform feed-forward multi-layer perceptron back propagation algorithm
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Mammogram Enhancement Using Lifting Dyadic Wavelet Transform and Normalized Tsallis Entropy 被引量:3
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作者 Muhammad Hussain 《Journal of Computer Science & Technology》 SCIE EI CSCD 2014年第6期1048-1057,共10页
In this paper, we present a new technique for mammogram enhancement using fast dyadic wavelet transform (FDyWT) based on lifted spline dyadic wavelets and normalized Tsallis entropy. First, a mammogram image is deco... In this paper, we present a new technique for mammogram enhancement using fast dyadic wavelet transform (FDyWT) based on lifted spline dyadic wavelets and normalized Tsallis entropy. First, a mammogram image is decom- posed into a multiscale hierarchy of low-subband and high-subband images using FDyWT. Then noise is suppressed using normalized Tsallis entropy of the local variance of the modulus of oriented high-subband images. After that, the wavelet coefficients of high-subbands are modified using a non-linear operator and finally the low-subband image at the first scale is modified with power law transformation to suppress background. Though FDyWT is shift-invariant and has better poten- tial for detecting singularities like edges, its performance depends on the choice of dyadic wavclcts. On the other hand, the nulnber of vanishing moments is an important characteristic of dyadic wavelets for singularity analysis because it provides an upper bound measurement for singularity characterization. Using lifting dyadic schemes, we construct lifted spline dyadic wavelets of different degrees with increased number of vanishing moments. We also examine the effect of these wavelets on mammogram enhancement. The method is tested on mammogram images, taken from MIAS (Mammographic Image Analysis Society) database, having various background tissue types and containing different abnormalities. The comparison with tile state-of-the-art contrast enhancement methods reveals that the proposed method performs better and the difference is statistically significant. 展开更多
关键词 mammogram enhancement lifting dyadic wavelet transform Tsallis entropy
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A New Method of CT Medical Images Contrast Enhancement 被引量:1
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作者 SUNFeng-rong LIUWei WANGChang-yu MEILiang-mo 《Chinese Journal of Biomedical Engineering(English Edition)》 2004年第1期28-38,共11页
A new method of contrast enhancement is proposed in the paper using multiscale edge representation of images, and is applied to the field of CT medical image processing. Comparing to the traditional Window technique, ... A new method of contrast enhancement is proposed in the paper using multiscale edge representation of images, and is applied to the field of CT medical image processing. Comparing to the traditional Window technique, our method is adaptive and meets the demand of radiology clinics more better. The clinical experiment results show the practicality and the potential applied value of our method in the field of CT medical images contrast enhancement. 展开更多
关键词 Contrast enhancement dyadic wavelet transform Multiscale edge representation Computed tomography
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A new iterative algorithm for reconstructing a signal from its dyadic wavelet transform modulus maxima
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作者 张茁生 刘贵忠 刘峰 《Science in China(Series F)》 2003年第6期420-430,共11页
A new algorithm for reconstructing a signal from its wavelet transform modulus maxima is presented based on an iterative method for solutions to monotone operator equations in Hilbert spaces. The algorithm's conve... A new algorithm for reconstructing a signal from its wavelet transform modulus maxima is presented based on an iterative method for solutions to monotone operator equations in Hilbert spaces. The algorithm's convergence is proved. Numerical simulations for different types of signals are given. The results indicate that compared with Mallat's alternate projection method, the proposed algorithm is simpler, faster and more effective. 展开更多
关键词 dyadic wavelet transform modulus maxima signal reconstruction monotone operator.
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