نتایج جستجو برای: wavelet coefficients
تعداد نتایج: 138766 فیلتر نتایج به سال:
A method for lossless image compression using wavelet lifting transform with automatic adjustment of wavelet filter coefficients for better compression is presented. The proposal is based on pattern recognition by 1-NN classifier. Using the pattern recognition, the lifting filter coefficients are optimized globally for each image. The proposed technique was aplied to test images and the compres...
In this work, a steganography technique using histogram shifting for JPEG2000 compressed images is proposed. Histogram of the wavelet coefficients of each wavelet subband is calculated and shifted to embed secret image data. This embedding is performed on the peak wavelet coefficients during wavelet decomposition process of JPEG2000 encoder using Lifting scheme. Optimal Pixel Adjustment Process...
This paper presents a new Quality-Controlled, wavelet based, compression method for electrocardiogram (ECG) signals. Initially, an ECG signal is decomposed using the wavelet transform. Then, the resulting coefficients are iteratively thresholded to guarantee that a predefined goal percent root mean square difference (GPRD) is matched within tolerable boundaries. The quantization strategy of ext...
Donoho and Johnstone (1997) studied a setting where data were obtained in the continuum white noise model and showed that scalar nonlinearities applied to wavelet coefficients gave estimators which were asymptotically minimax over Besov balls. They claimed that this implied similar asymptotic minimaxity results in the sampleddata model. In this paper we carefully develop and fully prove this im...
The gammachirp filter bank was used to model human cochlea filtering. Recently, we have proposed an auditory feature based on gammachirp wavelet transform. We have found that the features extractor gives a more significant improvement in robust speaker recognition than conventional acoustic features. The Gammachirp Wavelet Transform Frequency Cepestral Coefficients GWTFCC proposed the use of th...
This paper proposes a model for eliminating noise from ECG using α-trimmed thresholding. In this paper, the α-trimmed thresholding tested in the wavelet based Adaptive Filter Model. The Wavelet co-efficients at every sub-band level is made adapted by LMS algorithm to minimum mean square value and thresholded the adapted coefficients. It is shown that the proposed thresholding method offers vari...
This paper presents a steganography method using lossy compressed video which provides a natural way to send a large amount of secret data. The proposed method is based on 3-D set partitioning in hierarchical trees (SPIHT) algorithm for video compression and bit-plane complexity segmentation (BPCS) steganography. In 3-D SPIHT coding, wavelet coefficients in 3-D discrete wavelet transformed vide...
In the process of ventricular premature beat (PVC) and normal sinus rhythm (NSR) identification base on electrocardiogram (ECG), there exists problems like negative effect from ECG rhythm and low recognition rate. This paper proposes the electrocardiogram PVC classification algorithm based on support vector machine (SVM) and wavelet algorithm. The algorithm uses the wavelet transform to analyze...
Set Partioning in Hierarchical Trees (SPIHT) algorithm is a significant improvement of Embedded Zero Tree Wavelet (EZW) algoritm. It is based on the zero tree structure of EZW algorithm uses the smallest mean square error criterion.The most important wavelet coefficients are first encoded. It has got a good compression performance. The work is particularly targeted towards wavelet image compres...
Wavelet-domain hidden Markov tree (HMT) modeling provides a powerful approach to capture the underlying statistics of the wavelet coefficients. We develop a mutual information-based information-theoretic approach to quantify the interactions between the wavelet coefficients within a wavelet tree. This graphical method enables the design of a context-specific hidden Markov tree (HMT) by adding o...
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