in exploration seismology quality factor is widely used as a seismic attribute to identify anomalies related to attenuation, especially those caused by hydrocarbon. previous studies have indicated that seismic energy loss known as attenuation is greater for high frequency components of seismic data compared to the low frequency components. here the continuous wavelet transform is used to study ...

An image compression algorithm based on wavelet packet transform is introduced. The algorithm extends the parent-children link established across dyadic wavelet decomposition bands to a parent-children link across wavelet packet decomposition bands. Then, a method proposed for the efficient encoding of dyadic wavelet transform coefficients [1] is used for encoding of wavelet packet transform co...

Besides many advantages of wavelet transform, it has several drawbacks, e.g. ringing, shift variance, aliasing and lack of directionality. Some of them can be eliminated by using wavelet packet transform, stationary wavelet transform, complex wavelet transform, adaptive directional lifting-based wavelet transform, or adaptive wavelet filter banks that use either L2 or L1 norm. This paper contai...

The wavelet transform has become a useful computational tool for a variety of signal and image processing applications. For example, the wavelet transform is useful for the compression of digital image files; smaller files are important for storing images using less memory and for transmitting images faster and more reliably. The FBI uses wavelet transforms for compressing digitally scanned fin...

Introduction: SPECT is a diagnostic imaging technique the main disadvantage of which is the existence of Poisson noise. So far, different methods have been used by scientists to improve SPECT images. The Wavelet Transform is a new method for de-noising which is widely used for noise reduction and quality enhancement of images. The purpose of this paper is evaluation of noise reduction in SPECT ...

Asymptotic expansions of the wavelet transform for large and small values of the translation parameter b are obtained using asymptotic expansions of the Fourier transforms of the function and the wavelet. Asymptotic expansions of Mexican hat wavelet transform, Morlet wavelet transform, and Haar wavelet transform are obtained as special cases. Asymptotic expansion of the wavelet transform has al...

Medical ultrasound images are widely used for diagnostic purposes. A major problem regarding these images is in their inherent corruption by speckle noise. The presence of speckle noise severely hampers the interpretation and analysis of medical ultrasound images. The objective of the paper is to propose a method for removal of noise in the medical ultrasound images. The image noise content is ...

Other than the conventional fast Fourier transform (FFT) for multicarrier modulation, a new approach for multicarrier modulation (MCM) has been known. Meanwhile, multicarrier modulation involves dividing the broadband channel into many orthogonal but overlapping narrowband carriers. In an OFDM modulation based multicarrier system using the FFT, a cyclic prefix (CP) is inserted after each symbol...