Majid Foodeei - Academia.edu (original) (raw)
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Papers by Majid Foodeei
Proceedings of GLOBECOM '93. IEEE Global Telecommunications Conference, 1993
The discrete-time Gauss-Markov process is commonly used as a model in many source coding applicat... more The discrete-time Gauss-Markov process is commonly used as a model in many source coding applications. A highly correlated Gauss-Markov process models the intensity along the motion trajectories encountered in time varying image coding. We investigate the rate-distortion performance of lossy coding schemes operating on such sources in the practically important low bit-rate region of less than one bit per sample. Additional lossless entropy coding is assumed. Low complexity low bit-rate Code-Excited Linear Predictive (CELP) coders are designed, analyzed and simulated.
Proceedings of 1994 Workshop on Information Theory and Statistics, 1994
ABSTRACT The goal of this work is to analyze the advantages of the recently introduced entropy-co... more ABSTRACT The goal of this work is to analyze the advantages of the recently introduced entropy-constrained code-excited linear predictive (EC-CELP) quantization. The analysis is at low rates in comparison with other EC quantization schemes. Based on N-th order rate-distortion function (RDF), EC quantization theory, and empirical methods, RDF memory gain and empirical space-filling gain (dimensionality N) at low bit rates are defined and calculated. These gains categorize and help us analyze and compare the available coding gains for various EC coders for a given rate and delay (N)
Proceedings. IEEE Workshop on Speech Coding for Telecommunications, 1995
ABSTRACT Not Available
[Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing, 1991
A stochastic tree coder based on the (M,L) search algorithm suggested by V. Iyengar and P. Kabal ... more A stochastic tree coder based on the (M,L) search algorithm suggested by V. Iyengar and P. Kabal (1988) and a low-day CELP (code-excited linear prediction) coder proposed by J.H. Chen (1989) are considered. The individual components (predictors, gain adaptation, excitation coding) of the two coders are analyzed. The performances of the two types of coders are compared. The two coders
[Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing, 1991
| In this contribution an entropy-constrained code-excited linear predictive quantizer (EC-CELP) ... more | In this contribution an entropy-constrained code-excited linear predictive quantizer (EC-CELP) is introduced. EC-CELP addresses the problems associated with high quality, low delay, low complexity, low bit rate source coding of sources with memory. The motivation comes from the applications in motion-compensated time varying image compression. As well, there is an information theoretic interest in instrumentable coding schemes with performance near the rate-distortion bound having minimal delay and computational cost. EC-CELP implicitly combines the advantages of VQ, predictive coding (PC), and analysis-by-synthesis with the merits of the entropy-constrained codebook design. Simulation results show the clear advantages of EC-CELP over alternative schemes. EC-CELP quantization { Recently, it has been shown that a CELP coder followed by an entropy coder operating on a highly correlated Gauss-Markov source, has an excellent ratedistortion performance in the low bit-rate region 1]. To establish and extend those results to an entropy constrained context, and to obtain locally optimum variable-length predictive block coding with respect to a delity criterion, an extension of the entropy constrained VQ (ECVQ) 2] algorithm based on a Lagrangian formulation is introduced.
Proceedings of GLOBECOM '93. IEEE Global Telecommunications Conference, 1993
The discrete-time Gauss-Markov process is commonly used as a model in many source coding applicat... more The discrete-time Gauss-Markov process is commonly used as a model in many source coding applications. A highly correlated Gauss-Markov process models the intensity along the motion trajectories encountered in time varying image coding. We investigate the rate-distortion performance of lossy coding schemes operating on such sources in the practically important low bit-rate region of less than one bit per sample. Additional lossless entropy coding is assumed. Low complexity low bit-rate Code-Excited Linear Predictive (CELP) coders are designed, analyzed and simulated.
Proceedings of 1994 Workshop on Information Theory and Statistics, 1994
ABSTRACT The goal of this work is to analyze the advantages of the recently introduced entropy-co... more ABSTRACT The goal of this work is to analyze the advantages of the recently introduced entropy-constrained code-excited linear predictive (EC-CELP) quantization. The analysis is at low rates in comparison with other EC quantization schemes. Based on N-th order rate-distortion function (RDF), EC quantization theory, and empirical methods, RDF memory gain and empirical space-filling gain (dimensionality N) at low bit rates are defined and calculated. These gains categorize and help us analyze and compare the available coding gains for various EC coders for a given rate and delay (N)
Proceedings. IEEE Workshop on Speech Coding for Telecommunications, 1995
ABSTRACT Not Available
[Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing, 1991
A stochastic tree coder based on the (M,L) search algorithm suggested by V. Iyengar and P. Kabal ... more A stochastic tree coder based on the (M,L) search algorithm suggested by V. Iyengar and P. Kabal (1988) and a low-day CELP (code-excited linear prediction) coder proposed by J.H. Chen (1989) are considered. The individual components (predictors, gain adaptation, excitation coding) of the two coders are analyzed. The performances of the two types of coders are compared. The two coders
[Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing, 1991
| In this contribution an entropy-constrained code-excited linear predictive quantizer (EC-CELP) ... more | In this contribution an entropy-constrained code-excited linear predictive quantizer (EC-CELP) is introduced. EC-CELP addresses the problems associated with high quality, low delay, low complexity, low bit rate source coding of sources with memory. The motivation comes from the applications in motion-compensated time varying image compression. As well, there is an information theoretic interest in instrumentable coding schemes with performance near the rate-distortion bound having minimal delay and computational cost. EC-CELP implicitly combines the advantages of VQ, predictive coding (PC), and analysis-by-synthesis with the merits of the entropy-constrained codebook design. Simulation results show the clear advantages of EC-CELP over alternative schemes. EC-CELP quantization { Recently, it has been shown that a CELP coder followed by an entropy coder operating on a highly correlated Gauss-Markov source, has an excellent ratedistortion performance in the low bit-rate region 1]. To establish and extend those results to an entropy constrained context, and to obtain locally optimum variable-length predictive block coding with respect to a delity criterion, an extension of the entropy constrained VQ (ECVQ) 2] algorithm based on a Lagrangian formulation is introduced.