Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555529
M. Frikel, S. Bourennane
A method to estimate the set of bias vectors spanning the signal subspace without eigendecomposition is described. Each basis vector can be determined by the Lanczos algorithm. The signal subspace estimates at each frequency are transformed by focusing matrices such that the coherent signal subspace will be constructed for all analysis bands. The performance of the proposed method is shown to be almost the same as that of the classical eigendecomposition method.
{"title":"Direction finding for wideband signals using fast coherent signal subspace","authors":"M. Frikel, S. Bourennane","doi":"10.1109/DSPWS.1996.555529","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555529","url":null,"abstract":"A method to estimate the set of bias vectors spanning the signal subspace without eigendecomposition is described. Each basis vector can be determined by the Lanczos algorithm. The signal subspace estimates at each frequency are transformed by focusing matrices such that the coherent signal subspace will be constructed for all analysis bands. The performance of the proposed method is shown to be almost the same as that of the classical eigendecomposition method.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115371575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555499
R. M. Cesar, L. Costa
This paper introduces a novel framework for 2D shape analysis from its outline by using the Gabor transform (GT). The shape's boundary is represented by a complex signal, which is analyzed by the GT. Three automatic methods for analyzing the GT representation are discussed. Experimental results have shown that the GT can be used in the identification of dominant points as well as contour regions presenting periodic patterns (both deterministic and statistic patterns). Some results for synthetic and real images are presented and discussed.
{"title":"Shape characterization by using the Gabor transform","authors":"R. M. Cesar, L. Costa","doi":"10.1109/DSPWS.1996.555499","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555499","url":null,"abstract":"This paper introduces a novel framework for 2D shape analysis from its outline by using the Gabor transform (GT). The shape's boundary is represented by a complex signal, which is analyzed by the GT. Three automatic methods for analyzing the GT representation are discussed. Experimental results have shown that the GT can be used in the identification of dominant points as well as contour regions presenting periodic patterns (both deterministic and statistic patterns). Some results for synthetic and real images are presented and discussed.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124799746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555572
M. Mattavelli, J. Vesin, E. Amaldi, R. Gruter
Due to the inherent non-linearity and non-stationarity of a wide class of time series, nonlinear models have been the object of an increasing interest over the past years. Piecewise linear models, in which a linear sub-model is associated with each region of a state-space decomposition, have been proposed as an attractive alternative to threshold autoregressive models. However, it is still unclear how this type of models can be actually estimated. We show how a new combinatorial optimization approach, which we devised for the general problem of piecewise linear model estimation, can be successfully applied to piecewise linear modeling of time series. The idea is to focus on the inconsistent linear system that arises when considering a simple linear model and to partition it into a minimum number of consistent subsystems (MIN PCS). Although the resulting problem (MIN PCS) is NP-hard, satisfactory approximate solutions can be obtained using simple variants of the perceptron algorithm studied in the artificial neural network literature. Simulation results for two well-known chaotic time series are reported.
{"title":"A new approach to piecewise linear modeling of time series","authors":"M. Mattavelli, J. Vesin, E. Amaldi, R. Gruter","doi":"10.1109/DSPWS.1996.555572","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555572","url":null,"abstract":"Due to the inherent non-linearity and non-stationarity of a wide class of time series, nonlinear models have been the object of an increasing interest over the past years. Piecewise linear models, in which a linear sub-model is associated with each region of a state-space decomposition, have been proposed as an attractive alternative to threshold autoregressive models. However, it is still unclear how this type of models can be actually estimated. We show how a new combinatorial optimization approach, which we devised for the general problem of piecewise linear model estimation, can be successfully applied to piecewise linear modeling of time series. The idea is to focus on the inconsistent linear system that arises when considering a simple linear model and to partition it into a minimum number of consistent subsystems (MIN PCS). Although the resulting problem (MIN PCS) is NP-hard, satisfactory approximate solutions can be obtained using simple variants of the perceptron algorithm studied in the artificial neural network literature. Simulation results for two well-known chaotic time series are reported.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128347425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555526
S. Bourennane, M. Frikel
We present a noneigenvector algorithm for the DOA estimator calculation. This algorithm is based on the partitioning of the cross-spectral matrix. An operator, the so-called propagator, is estimated. It has been shown that the propagator has the same properties as the noise subspace. The proposed algorithm is very effective in computations and resolves the source localization problem in the presence of the correlated noise. The simulation results concerning the performance of the developed method are presented.
{"title":"New method for locating the wideband sources","authors":"S. Bourennane, M. Frikel","doi":"10.1109/DSPWS.1996.555526","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555526","url":null,"abstract":"We present a noneigenvector algorithm for the DOA estimator calculation. This algorithm is based on the partitioning of the cross-spectral matrix. An operator, the so-called propagator, is estimated. It has been shown that the propagator has the same properties as the noise subspace. The proposed algorithm is very effective in computations and resolves the source localization problem in the presence of the correlated noise. The simulation results concerning the performance of the developed method are presented.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127769454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555502
Huiwei Guan, T. Cheung, Chi-Kwong Li
Distributed multimedia technology has emerged in the last few years as a major research area. The real-time transmission of image (RTTI) on a distributed system is one of key techniques in the area. Several practical RTTI techniques in a distributed multiple servers network are proposed, which include XView, Xt and Widget, and Xlib programming implementations. Our design scheme has the following advantages: firstly, it only needs to equip a X-based video card on the local machine so that the device cost of communications on a distributed system is reduced; secondly, it just needs to code one client application program, which reduces the programming work; and thirdly, it has fine expansiveness and flexibility.
{"title":"Several practical client/server programming implementations for real-time transmission of image in X window environment","authors":"Huiwei Guan, T. Cheung, Chi-Kwong Li","doi":"10.1109/DSPWS.1996.555502","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555502","url":null,"abstract":"Distributed multimedia technology has emerged in the last few years as a major research area. The real-time transmission of image (RTTI) on a distributed system is one of key techniques in the area. Several practical RTTI techniques in a distributed multiple servers network are proposed, which include XView, Xt and Widget, and Xlib programming implementations. Our design scheme has the following advantages: firstly, it only needs to equip a X-based video card on the local machine so that the device cost of communications on a distributed system is reduced; secondly, it just needs to code one client application program, which reduces the programming work; and thirdly, it has fine expansiveness and flexibility.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116298961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555550
N. Ivanov
The fact that the elements of two dimensional (2D) arrays, processed by a computer, are sampled on space and quantities in the range /spl plusmn/2/sup n/, permits its treatment as elements of integer fields Z/sub m/. Within the limits of this field, an orthogonal set of functions could be build. These functions form a basis of general Fourier-Galois transformations. The features of these transformations are very close to the well known transformation of Fourier, observe the theorem of time-frequency duality and permit realization of error free calculation of spectra. In cases when powers of 2 are used as twiddle factors, this transformation is known as the number theoretic transform (NTT). In order to improve the practical use of the generalized Fourier-Galois transform, for digital signal processing, this paper presents a study of a method for calculating the two dimensional NTT.
{"title":"Calculation of two dimensional number transform-an analytical study","authors":"N. Ivanov","doi":"10.1109/DSPWS.1996.555550","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555550","url":null,"abstract":"The fact that the elements of two dimensional (2D) arrays, processed by a computer, are sampled on space and quantities in the range /spl plusmn/2/sup n/, permits its treatment as elements of integer fields Z/sub m/. Within the limits of this field, an orthogonal set of functions could be build. These functions form a basis of general Fourier-Galois transformations. The features of these transformations are very close to the well known transformation of Fourier, observe the theorem of time-frequency duality and permit realization of error free calculation of spectra. In cases when powers of 2 are used as twiddle factors, this transformation is known as the number theoretic transform (NTT). In order to improve the practical use of the generalized Fourier-Galois transform, for digital signal processing, this paper presents a study of a method for calculating the two dimensional NTT.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121773885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555480
Y.-P. Lin, P. Vaidyanathan
It is known that a continuous time signal x(t) with Fourier transform X(/spl nu/) band-limited to |/spl nu/|
已知傅里叶变换x(/spl nu/)带限为|/spl nu/|
{"title":"Periodically nonuniform sampling of a new class of bandpass signals","authors":"Y.-P. Lin, P. Vaidyanathan","doi":"10.1109/DSPWS.1996.555480","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555480","url":null,"abstract":"It is known that a continuous time signal x(t) with Fourier transform X(/spl nu/) band-limited to |/spl nu/|</spl Theta//2 can be reconstructed from its samples x(T/sub 0/n) with T/sub 0/=2/spl pi///spl Theta/. In the case that X(/spl nu/) consists of two bands and is band-limited to /spl nu//sub 0/<|/spl nu/|</spl nu//sub 0/+/spl Theta//2, successful reconstruction of x(t) from x(T/sub 0/n) requires that these two bands be located properly. When the two bands are not located properly, Kohlenberg (1953) showed that we can use a periodically nonuniform sampling (PNS) scheme to recover x(t). In this paper, we show that PNS scheme can be generalized and applied to a wider class. Further generalizations will be made to two-dimensional case and discrete-time case.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"206 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122978839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555532
E. Kuruoğlu, P. Rayner, W. Fitzgerald
A new nonlinear filtering technique is introduced for the elimination of impulsive noise modelled with a symmetric /spl alpha/-stable (S/spl alpha/S) distribution. The new algorithm, called polynomial iteratively reweighted least squares (PIRLS), employs a Volterra filter the coefficients of which are estimated by minimizing the l/sub p/-norm of the estimation error. The filter, hence constructed, is used to estimate the clean data from the corrupted data. Simulation results obtained for audio data corrupted by synthetic S/spl alpha/S noise indicate that PIRLS is very successful in removing impulsive noise.
{"title":"Impulsive noise elimination using polynomial iteratively reweighted least squares","authors":"E. Kuruoğlu, P. Rayner, W. Fitzgerald","doi":"10.1109/DSPWS.1996.555532","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555532","url":null,"abstract":"A new nonlinear filtering technique is introduced for the elimination of impulsive noise modelled with a symmetric /spl alpha/-stable (S/spl alpha/S) distribution. The new algorithm, called polynomial iteratively reweighted least squares (PIRLS), employs a Volterra filter the coefficients of which are estimated by minimizing the l/sub p/-norm of the estimation error. The filter, hence constructed, is used to estimate the clean data from the corrupted data. Simulation results obtained for audio data corrupted by synthetic S/spl alpha/S noise indicate that PIRLS is very successful in removing impulsive noise.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"197 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116408550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555462
J. Liang, T. Parks
We introduce a new translation invariant wavelet transform algorithm with symmetric extensions that has the following desirable properties: (1) translation invariance, (2) reduced edge effects, and (3) size-limitedness. We demonstrate the improvement gained by this new algorithm with both a synthetic example and coding results using a standard test image. We combine our previous work on translation invariant wavelet transform algorithm with circular extensions with work on size-limited filter banks.
{"title":"Translation invariant wavelet transforms with symmetric extensions","authors":"J. Liang, T. Parks","doi":"10.1109/DSPWS.1996.555462","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555462","url":null,"abstract":"We introduce a new translation invariant wavelet transform algorithm with symmetric extensions that has the following desirable properties: (1) translation invariance, (2) reduced edge effects, and (3) size-limitedness. We demonstrate the improvement gained by this new algorithm with both a synthetic example and coding results using a standard test image. We combine our previous work on translation invariant wavelet transform algorithm with circular extensions with work on size-limited filter banks.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134010076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1996-09-01DOI: 10.1109/DSPWS.1996.555459
A. Fuldseth, T. Ramstad
The use of leaky prediction in a video transmission system designed for noisy channels is investigated. For the proposed system, graceful degradation is achieved by finding good index maps between the quantized source coder parameters and the amplitude levels of a QAM signal constellation. The paper, however, investigates the use of leaky prediction to further increase the robustness to channel noise. It is shown that by using a temporal prediction coefficient slightly less than one, large improvements can be achieved with only a small degradation for the noiseless case. The performance of the proposed system is comparable to a reference system based on the H.263 video coder for high CSNR values, and degrades far more gracefully for low CSNR values.
{"title":"Robust subband video coding with leaky prediction","authors":"A. Fuldseth, T. Ramstad","doi":"10.1109/DSPWS.1996.555459","DOIUrl":"https://doi.org/10.1109/DSPWS.1996.555459","url":null,"abstract":"The use of leaky prediction in a video transmission system designed for noisy channels is investigated. For the proposed system, graceful degradation is achieved by finding good index maps between the quantized source coder parameters and the amplitude levels of a QAM signal constellation. The paper, however, investigates the use of leaky prediction to further increase the robustness to channel noise. It is shown that by using a temporal prediction coefficient slightly less than one, large improvements can be achieved with only a small degradation for the noiseless case. The performance of the proposed system is comparable to a reference system based on the H.263 video coder for high CSNR values, and degrades far more gracefully for low CSNR values.","PeriodicalId":131323,"journal":{"name":"1996 IEEE Digital Signal Processing Workshop Proceedings","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134338523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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