the s-transform has widely been used in the analysis of non-stationary time series. a simple method to obtain depth estimates of gravity field sources is introduced in this study. we have developed a new method based on the spectral characteristics of downward continuation to estimate depth of structures. this calculation procedure is based on replacement of the fourier transform with the s-tra...

s is a time-frequency transform based on the concept of short-time fourier transform and wavelet transform. the main property of this transform that separate it from the discrete short-time fourier transform is variable frequency resolution. but in this transform the change of resolution of high frequencies to low frequencies is very high. so another transform as a modified s transform is intro...

this paper presents a new coding method for image compression based on jpeg2000 and contourlet transform. jpeg2000 standard is a common standard that uses discrete wavelet transform (dwt) in the compression process. the main problems of dwt are failure to detect curved edges in image and its shortage representation of the ridge and furrow patterns which cause deficiency and block artifacts rema...

The Scale transform is a new representation for signals, offering perspective different from the Fourier transform. In this paper, we introduce the notion of a scale periodic function. These functions are then represented through the discrete scale series. We also define the notion of a strictly scale limited signal. Analogous to the Shannon interpolation formula, we show that such signals can ...

A specific form of the Mellin transform, referred to as the “scale transform,” is known to be a natural complement to the Fourier transform for wideband analytic signals. In this paper, limitations for the simultaneous localization of scale transform pairs are investigated. A number of inequalities are established and discussed, based on various measures of spread (Heisenberg-type inequalities ...

Recently, a 'gammachirp' function has been derived as an optimal auditory filter function in terms of minimal uncertainty in a joint time and modified-scale representation if the scale transform defined by Cohen is used in the auditory system. The gammatone function, which is widely used as the impulse response of a linear auditory filter, is a first-order approximation of the 'gammachirp' func...

We present algorithms for the type-IV discrete cosine transform (DCT-IV) and discrete sine transform (DSTIV), as well as for the modified discrete cosine transform (MDCT) and its inverse, that achieve a lower count of real multiplications and additions than previously published algorithms, without sacrificing numerical accuracy. Asymptotically, the operation count is reduced from 2N log2 N +O(N...

Transform-domain adaptive lters refer to LMS lters whose inputs are preprocessed with a unitary data-independent transformation followed by a power normalization stage. The transformation is typically chosen to be the discrete Fourier transform (DFT), although other transformations such as the cosine transform (DCT), the Hartley transform (DHT), or the Walsh-Hadamard transform, have also been p...