This paper describes an estimation and representation method for object structure in 3D image data. A windowed Fourier transform is used to estimate the parameters of 3D local structures (lines, planes and spheres) across a number of window sizes or scales. We present the estimation method and describe a decision process which aims to find the simplest object description. Results of the method ...

In this paper, we describe and demonstrate how the combined use of Wigner and STFT processing can be used to advantage in a sound understanding application. Speciically, the Wigner processing of a signal is used for alerting the signal understanding system to the possibility of inadequate time or frequency resolution in the STFT processing of the same signal. The signal understanding system may...

This paper describes techniques for obtaining high accuracy estimates, including those of non-stationarity, of parameters for sinusoidal modelling using a single frame of analysis data. In this case the data used is generated from the time and frequency reassigned short-time Fourier transform (STFT). Such a system offers the potential for quasi real-time (frame-by-frame) spectral modelling of a...

/2 ( ) ( ) u u        where  is the Fourier transformation and  its inverse. The question is to determine for which values of the exponents pi and qi the only nonnegative solution (u, v) of (1) and (2) is trivial, i.e., (u; v) = (0, 0). When 2   , is the case of the Emden-Fowler equation 0 , 0     u u u k in N  (5) When ) 3 )( 2 /( ) 2 ( 1      N N N k , it has been prove...

This paper presents the theoretical background for the Model Based Underdetermined Source Separation presented in [5]. We show that for a given frequency band, in contrast to customary assumption, the observed Short-Time Fourier Transform (STFT) ratio coming from one source is not constant in time, but is a random variable whose distribution we have obtained. Using this distribution and the Tim...

• Non-negative matrix factorization (NMF) [3] solves V ≈ WH • V is the f -by-t magnitude STFT of the audio • W contains note spectra in its columns and represents the source model(s) • H contains note activations in its rows and gives the transcription • Rank of decomposition corresponds to number of distinct pitches • Can handle multiple instruments by interpreting W and H in block-form (i.e. ...

<p style='text-indent:20px;'>In this paper, we consider a quaternionic short-time Fourier transform (QSTFT) with normalized Hermite functions as windows. It turns out that such is based on the recent theory of slice polyanalytic quaternions. Indeed, will use notions true and full Fock spaces Segal-Bargmann transforms. We prove new properties QSTFT including Moyal formula, reconstruction f...

Fourier Wavefront Reconstruction Over a Rectangular Pupil The iterative and boundary methods developed here for circular and elliptical pupils are based on a method to reconstruct the wavefront over the rectangular pupil. To fully understand this development, it is necessary to first summarize the approach used by Freischlad and Koliopoulos to derive an inverse spatial filter to reconstruct a w...