Kwan Truong - Academia.edu (original) (raw)

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Papers by Kwan Truong

La presente invention concerne des systemes et procedes permettant de relier en mode numerique pl... more La presente invention concerne des systemes et procedes permettant de relier en mode numerique plusieurs microphones et de generer les signaux des microphones. Certains modes de realisation portent sur la liaison en mode numerique de plusieurs systemes de melangeurs automatiques dans le cas ou l'on a besoin d'un grand nombre de microphones. Dans les grands systemes de melangeurs automatiques, les canaux d'entree des microphones peuvent etre distribues entre de nombreux dispositifs. Plutot que d'emettre ces signaux individuellement en direction d'un dispositif de traitement central destine au melangeur automatique, il est plus efficace de distribuer les fonctions de traitement du signal audio du melangeur de microphones automatiques entre plusieurs dispositifs dans un systeme audio de sonorisation de conference. Il en resulte qu'on peut emettre entre les dispositifs un moindre nombre d'assortiments filtres de signaux de microphones. Les modes de realisatio...

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Proceedings of 1st International Conference on Image Processing

ABSTRACT A hierarchical coder (HC) is constructed from a number of simple coders for image blocks... more ABSTRACT A hierarchical coder (HC) is constructed from a number of simple coders for image blocks arranged in order of increasing bit rate and reproduction quality. This paper discusses several aspects of hierarchical coders, including: a general description of the structure of a HC, its advantages and important design considerations, a discussion of how threshold selection can affect the performance of the coder through a simple example, and an introduction of a simple procedure for selecting optimal (in the rate distortion sense) decision thresholds which control the levels of the hierarchy

1999 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258), 1999

This paper presents an improved mixed excitation linear prediction (MELP) coder. The MELP is the ... more This paper presents an improved mixed excitation linear prediction (MELP) coder. The MELP is the linear-prediction-based speech coder that was chosen as the new 2400 bps US Federal Standard. Even though the MELP is quite good, there are still some perceivable distortions, particularly around non-stationary speech segments and for some low-pitch male speakers. The key features of our new coder include a robust pitch detection algorithm, a new plosive analysis/synthesis method, and a post processor for the Fourier magnitude model. Formal quality tests are used to show that the new MELP improves the quality of the US Federal Standard MELP coder while requiring only a small increase in algorithmic delay and while also retaining compatibility with the Federal Standard MELP bit-stream specification

1996 IEEE International Conference on Acoustics, Speech, and Signal Processing Conference Proceedings

... Alan McCreel Kwan Truong' E. Bryan George' Thomas P. Barnwell2 Vishu Vzswanathanl .... more ... Alan McCreel Kwan Truong' E. Bryan George' Thomas P. Barnwell2 Vishu Vzswanathanl ... Listening tests con-firm that the enhanced 2.4 kbit/s MELP coder performs as well as the higher bit rate 4.8 kbit/s FS1016 CELP stan-dard. ...

Visual Communications and Image Processing '94, 1994

ABSTRACT This paper looks at some of the challenges associated with building a coder for video te... more ABSTRACT This paper looks at some of the challenges associated with building a coder for video telephony that operates at bit rates below 20 kbps. It then proceeds to present a novel hierarchically structured coder that provides a mechanism for addressing many of these difficulties. The hierarchical structure employs several different simple predictors that are ordered according to their coding gains. This structure is contrasted with traditional predictive coders for video head and shoulders sequences and its performance is demonstrated with several examples.

Proceedings. IEEE Workshop on Speech Coding for Telecommunications

... We have in-vestigated two primary approaches to improving this MELP model: Fourier series cod... more ... We have in-vestigated two primary approaches to improving this MELP model: Fourier series coding and mel-scale LPC. 2.1. ... 2.2. Mel-Scale LPC The improvements due to Fourier magnitude coding suggest that an improved LPC spectral fit would increase speech quality. ...