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Harmonic wavelet transform

About: Harmonic wavelet transform is a research topic. Over the lifetime, 9602 publications have been published within this topic receiving 247336 citations.


Papers
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Journal ArticleDOI
TL;DR: The maximum entropy method (MEM) is applied to the interferogram data obtained using the technique of Fourier transform spectroscopy for estimating its spectrum with a resolution far exceeding the value set by the spectrometer.
Abstract: The maximum entropy method (MEM) is applied to the interferogram data obtained using the technique of Fourier transform spectroscopy for estimating its spectrum with a resolution far exceeding the value set by the spectrometer. For emission line data, the MEM process is directly used with the interferogram data in place of the regular Fourier transformation process required in Fourier transform spectroscopy. It produces a spectral estimate with an enhanced resolution. For absorption data with a broad background spectrum, the method is applied to a modified interferogram which corresponds to the Fourier transform of the absorptance spectrum. Two results are presented to demonstrate the power of the technique: for the visible emission spectrum of a spectral, calibration lamp and for the infrared chloroform absorption spectrum. Included in the paper is a discussion of the problems associated with practical use of the MEM.

53 citations

Book ChapterDOI
30 Nov 2004
TL;DR: It is shown that the proposed transform domain conversion outperforms the conventional pixel domain approach and is expected to have applications in transform domain video transcoding.
Abstract: Many video coding schemes, including MPEG-2, use a Discrete Cosine Transform (DCT). The recently completed video coding standard, H.264/AVC, uses an integer transform, which will be referred to as HT in this paper. We propose an efficient method to convert DCT coefficients to HT coefficients entirely in the transform domain. We show that the conversion is essentially a 2D transform. We derive the transform kernel matrix, provide a fast algorithm and an integer approximation of the transform. We show that the proposed transform domain conversion outperforms the conventional pixel domain approach. It is expected to have applications in transform domain video transcoding.

52 citations

Journal ArticleDOI
TL;DR: Kingsbury's dual-tree complex wavelet transform in the frequency domain is examined, where it can be formulated for standard wavelet filters without special filter design and applied to the classification of signals.
Abstract: We examine Kingsbury's dual-tree complex wavelet transform in the frequency domain, where it can be formulated for standard wavelet filters without special filter design and apply the method to the classification of signals. The obtained transforms achieve low shift sensitivity and better directionality compared to the real discrete wavelet transform while retaining the perfect reconstruction property.

52 citations

Proceedings ArticleDOI
06 Apr 1995
TL;DR: Adaptive time-frequency wavelet transform is applied to ISAR image reconstruction and a simulation procedure is developed to describe the characteristics of the algorithm.
Abstract: Inverse synthetic aperture radar (ISAR) uses target's motion to generate images on the range- Doppler plane. The conventional ISAR uses Fourier transform to compute Doppler spectrum for each range cell. Due to the target irregular translational and rotational motion, the Doppler frequency in fact is time-varying. By using Fourier transform, the reconstructed image becomes blurred. To represent time-varying Doppler spectrum, time-frequency transform should be utilized. Adaptive time-frequency wavelet transform is a very useful tool in analysis of signals with time-varying spectrum. We applied adaptive time-frequency wavelet transform to ISAR image reconstruction and developed a simulation procedure to describe the characteristics of the algorithm. By replacing the conventional Fourier processor with the adaptive wavelet processor, a 2-D range-Doppler Fourier ISAR frame becomes a 3-D time- range-Doppler wavelet ISAR cube. By sampling in time, a time sequence of 2-D range- Doppler images can be viewed. Each individual wavelet ISAR image provides not only superior resolution but also the temporal information within each frame time. Both simulated and real ISAR data have been tested. The result from simulated ISAR data is illustrated in this paper.

52 citations

Journal ArticleDOI
TL;DR: The authors apply the wavelet transform to the analysis of EMG signals by exploiting the fact that, under certain conditions, the signal can be considered as the sum of scaled and delayed versions of a single prototype.
Abstract: The authors apply the wavelet transform to the analysis of EMG signals. Exploiting the fact that, under certain conditions, the signal can be considered as the sum of scaled and delayed versions of a single prototype, we have chosen the mother wavelet so as to match the known shape of the basic component. Moreover, the input signal has been Shannon interpolated in order to improve the low scale resolution. The results in terms of MUAP detection and resolution are very encouraging, even in the presence of high levels of noise.

52 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202323
202274
20213
20207
20196
201831