Discrete cosine harmonic wavelet transform and its application to signal compression and subband spectral estimation using modified group delay

Narasimhan, SV and Harish, M and Haripriya, AR and Basumallick, Nandini (2008) Discrete cosine harmonic wavelet transform and its application to signal compression and subband spectral estimation using modified group delay. Signal, Image and Video Processing. pp. 1-26.

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Abstract

This paper proposes a new harmonic wavelet transform (HWT) based on13; Discrete Cosine Transform (DCTHWT) and its application for signal or image13; compression and subband spectral estimation using Modified Group Delay (MGD).13; Further, the existing DFTHWT has also been explored for image compression. The13; DCTHWT provides better quality decomposed decimated signals, which enable13; improved compression and MGD processing. For signal/image compression, compared13; to the HWT based on DFT (DFTHWT), the DCTHWT reduces the reconstruction error.13; Compared to DFTHWT for the speech signal considered for a compression factor of13; 0.62, the DCTWHT provides a 30% reduction in reconstruction error. For an image, the13; DCTHWT algorithm due to its real nature, is computationally simple and more accurate13; than the DFTHWT. Further compared to Cohen-Daubechies-Feauveau 9/7 biorthogonal13; symmetric wavelet, the DCTHWT, with its computational advantage, gives a better or13; comparable performance. For an image with 6.25% coefficients, the reconstructed13; image by DFTHWT is significantly inferior in appearance to that by DCTHWT which13; is reflected in the error index as its values are 3.0% and 2.65% respectively.13; For spectral estimation, DCTHWT reduces the bias both in frequency13; (frequency resolution) and spectral magnitude. The reduction in magnitude bias in turn13; improves the signal detectability. In DCTHWT, the improvement in frequency13; resolution and the signal detectability is not only due to good quality DCT subband13; signals but also due to their stretching (decimation) in the wavelet transform. The MGD13; reduces the variance while preserving the frequency resolution achieved by DCT and13; decimation. In view of these, the new spectral estimator facilitates a significant13; improvement both in magnitude and frequency bias, variance and signal detection13; ability; compared to those of MGD processing of both DFT and DCT fullband and DFT13; subband signals

Item Type:	Article
Additional Information:	Copyright for this article belongs to Springer-Verlag
Uncontrolled Keywords:	DCT harmonic wavelet transform;Signal and image compression;Subband spectral estimation;Modified group delay
Subjects:	ENGINEERING > Electronics and Electrical Engineering AERONAUTICS > Aeronautics (General)
Depositing User:	Ms. Alphones Mary
Date Deposited:	30 Apr 2008
Last Modified:	17 Jun 2010 05:45
URI:	http://nal-ir.nal.res.in/id/eprint/4708

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