Papers by adriaan Ligtenberg
Reconnaissance de formes appliquée aux signaux électrocardiographiques en vue d'une surveillance automatique
These Ecole polytechnique federale de Lausanne EPFL, n° 526 (1984)Institut de genie electrique et... more These Ecole polytechnique federale de Lausanne EPFL, n° 526 (1984)Institut de genie electrique et electroniqueLaboratoire de traitement des signaux 1 Reference doi:10.5075/epfl-thesis-526Print copy in library catalog Record created on 2005-03-16, modified on 2016-08-08
Architecture of a communication network processor
PARLE '89 Parallel Architectures and Languages Europe, 1989
This article describes the architecture and the design of a high speed packet-switched communicat... more This article describes the architecture and the design of a high speed packet-switched communication network for multi-processor systems. It consists of a autonomous communication layer connected to a computational layer. The proposed network architecture uses a store and forward communication mechanism to maximally share resources. Each node in the network dynamically forwards messages between a source and a destination using
JPEG/sup ++/: selective compression for high quality color desktop publishing
COMPCON Spring '91 Digest of Papers
The JPEG (Joint Photographic Experts Group) algorithm is the international standard for still ima... more The JPEG (Joint Photographic Experts Group) algorithm is the international standard for still image compression and has already been implemented in some video display systems and color scanners. An extension to JPEG, known as JPEG/sup ++/, allows a far greater range of compression and quality options for graphics users. To complete the implementation of compression in the graphics production chain, JPEG will be implemented in color printers. The authors provide an overview of the JPEG compression standard and the JPEG/sup ++/ extension and discuss their application to high-quality color desktop publishing.<<ETX>>
Algorithm-architecture mapping for custom DSP chips
1988., IEEE International Symposium on Circuits and Systems
In the design of custom VLSI chipsd for digital signal processing (DSP) applications, a good algo... more In the design of custom VLSI chipsd for digital signal processing (DSP) applications, a good algorithm-architecture mapping is critical to achieve efficiency and high performance. It is shown how an efficient mapping can be derived not only by adapting an architecture to a given algorithm, but also by changing the algorithm&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s description in a systematic way. A tool under development
EDA and the Internet (panel session)
ABSTRACT
EDA and the Internet (panel session (title only))
Proceedings of the 2000 international symposium on Physical design - ISPD '00, 2000
Secure inter-company collaboration environment
The Emerging Compression Standard for Continuous Tone Images and Its Potential for Color Fax
1990 Conference Record Twenty-Fourth Asilomar Conference on Signals, Systems and Computers, 1990.
Color Fdx and other emerging applications, such as full color (24-bit) desktop publishing and pho... more Color Fdx and other emerging applications, such as full color (24-bit) desktop publishing and phot ovi deo t ex (supported by 2 4 bit c o 1 o r scanners, monitors, printers and cameras], need data reduction and standards to reach acceptable price/performance levels. To attain this goal a joint committee of the CCITT and I S 0 standard organizations was formed, the Joint Photographic Expert Group CJPEG]. JPEG’s objective is to develop and to standardize an efficient method for the compression of color images. The JPEG standard is designed to be flexible and to satisfy a broad range of applications. The selected algorithm is a lossy technique based o n the discrete cosine transform, a uniform quantizer and followed by entropy encoding. The standard consists of three parts: a baseline system; an extended system; and a separate lossless function. This paper will give an overview of the current status of the JPEG standard and its potential for color FAX
International Conference on Acoustics, Speech, and Signal Processing,
A new class of practical fast algorithms is introduced for the Discrete Cosine 'nunsfom (DCT), a ... more A new class of practical fast algorithms is introduced for the Discrete Cosine 'nunsfom (DCT), a n important transform that is of particular interest i n image compression. For a n 8-point DCT only 11 multiplications and 29 additions are required. A systematic approach is presented to generate t h e different members in this class all having the same mini m u m arithmetic complexity. T h e structure of many of t h e published algorithms can be found in members of this class. An extension of t h e algorithm for longer transformations is presented. As a result, the 16-point DCT requires only SI multiplications a n d 81 additions, which is, to our knowledge, less t h a n t h e currently published algorithms.
Abstract-An 8-point Fourier-cosine transform chip designed for a data rate of 100 Mbits/s is desc... more Abstract-An 8-point Fourier-cosine transform chip designed for a data rate of 100 Mbits/s is described. The top-down design is presented step by step, including algorithm modification for VLSI suitability, architectural choices, testing overhead, internal precision assignments, mask generation,, and finally, verification of the layout. A high-level language (C) design tool was developed concurrently with the layout. This tool allows mimicking exactly the different representations of the algorithm: software, mask, and chip. This provides an automatic cross-checking at all design stages. The VLSI environment created by this tool, as well as existing powerful CAD tools, made a fast design-time possible. H I.
This document is provided for general informational use. No responsibility is assumed by the auth... more This document is provided for general informational use. No responsibility is assumed by the authors with regard to the accuracy of the information contained herein. The documentation described herein may be used, copied, or transcribed without fee or prior agreement provided that acknowledgement or reference is made of the source. Sun is a trademark of Sun Microsystems, Inc. UNIX is a trademark of AT&T. DECstation is a trademark of Digital Equipment Corporation. This package is based on the UNIX operating system. We appreciate any comments or corrections-they can be sent to Andy C. Hung at [email protected]. We cannot guarantee that any bugs will be corrected however. Funded by the Defense Advanced Research Projects Agency. I am especially grateful to Hewlett Packard and Storm Technology for their financial support during the earlier stages of codec development. Any errors in the code and documentation are my own. The following people are acknowledged for their advice and assi...
Authorizing an Advance Payment Based on Performer Data
Automated ECG monitoring based on pattern recognition principle (Original French title: 'Reconnaissance de formes appliquée aux signaux éléctrocardiographique en vue d'une surveillance automatique')
Signal Processing, 1984
VLSI for pattern recognition and image processingKing-sun Fu, published by: Springer, Berlin/Heidelberg/New York/Tokyo, 1984
Signal Processing, 1986
Signal Processing, 1986
A framework supported by a set of tools for turning digital signal processing algorithms into cus... more A framework supported by a set of tools for turning digital signal processing algorithms into custom chips is proposed. The framework, called MOVAL, integrates analysis, layout synthesis and validation and is based on a structured top-down design methodology covering seven succinct abstraction levels: the behavioral, data representation, space/time, hardware, symbolic and geometric (mask) descriptions, and the chip. The top four levels efficiently cope with the implementation trade-offs and are all written in the same high level language, currently “C”. As a result, the design can be modeled using a mixture of components defined at different abstraction levels. This allows an efficient mixed-mode multi-level validation. The hardware description is unambiguous and is the key to (semi-) automatic synthesis of the layout. Furthermore, it generates test vectors for the symbolic layout, the mask and, finally, the chip. The validation is done automatically, based on back substitution. As an example of the proposed design methodology, the crucial steps of the implementation of a fast Fourier cosine transform algorithm are described.Ein Entwicklungskonzept mit Werkzeugen wird vorgeschlagen um Signalverarbeitungsalgorithmen in spezialisierte Chips umzuwandeln. Das Konzept, MOVAL genannt, integriert die Analyse, die Synthese und die Verifikation, und ist eine strukturierte ‘top-down’ Methodologie mit sieben Abstraktionsniveaus: Algorithmus, Datenpräzision, Raum/Zeit, Hardware, symbolisches Layout, Masken, und Chip. Die vier oberen Niveaus erlauben es, die verschiedenen Kompromisse einer Implementation zu erforschen, und sie sind in der gleichen hohen Sprache, “C”, geschrieben. Deshalb kann der Design mit Komponenten modelisiert werden die auf verschiedenen Niveaus geschrieben sind. Dies erlaubt eine effiziente, ‘mixed-mode, multi-level’ Verifikation. Die hardware Beschreibung ist eindeutig und erlaubt eine (semi-) automatische Layout-Synthese. Damit können auch Testvektoren generiert werden, und dies sowohl für das symbolische Layout wie für die Masken und das Chip. Die Verifikation ist automatisch und basiert auf die Rückwärts-Substitution. Als Beispiel für diese Design Methodologie werden die wichtigen Etappen des Designs eines ‘fast cosine transform’ Chips gezeigt.Dans cette contribution, on propose un contexte de développement et certains outils afin de transformer des algorithmes de traitement du signal en circuits intégrés spécialisés. Ce contexte de développement, appelé MOVAL, intègre l'analyse, la synthèse du schéma ainsi que la validation. Il est basé sur une méthodologie ‘top-down’ structurée et faisant appel à sept niveaux d'abstraction: le niveau algorithmique, de précision finie, d'espace/temps, de matériel, de schéma symbolique, de masque, et finalement le niveau physique (circuit). Les quatre niveaux supérieurs permettent d'explorer efficacement les compromis possibles lors de l'implantation et sont tous quatre écrits dans un langag commun de haut niveau, le “C”. Ainsi, on peut simuler un circuit en utilisant des éléments décrits à des niveaux d'abstraction différents. Ceci permet une validation en modes et niveaux mélangés. La description matérielle est non ambiguë et permet une génération (semi-) automatique du schéma symbolique. De surcroît, elle permet la génération de vecteurs de test, tant pour le schéma symbolique que pour le plan de masques ou le circuit physique. La validation est faite automatiquement par voie de substitution. Comme exemple, on montre les étapes principales du développement d'un circuit réalisant une transformation en cosinus rapide.
Preprocessing of electrocardiograms by digital techniques
Signal Processing, 1982
A simple but powerful digital band-pass filter is proposed for the preprocessing of ECG signals. ... more A simple but powerful digital band-pass filter is proposed for the preprocessing of ECG signals. It consists of two parallel triangular filters implemented recursively. The application of this filter to noisy ECG signals shows that baseline variations are removed, the powerline component and its higher harmonics are suppressed quite successfully and artefacts are considerably attenuated. This filtering is necessary as preprocessing when extracting features for automated classification of arrythmia.Für die Vorverarbeitung von EKG-Signalen wird einfaches, aber sehr wirkungsvolles digitales Bandpassfilter vorgeslagen. Es besteht aus zwei parallelen Dreiecksfilters, die rekur implementiert wurden. Die Anwendung dieses Filters auf rauschbehaftete EKG-Signale zeigt, dass Variationen der Basislinie entfernt werden, der Netzbrumm inklusive seiner höheren Harmonischen recht erfolgreich unterdruckt und Störungen betrachtlich gedämpft werden konnten. Diese Filterung ist eine nötige Vorverarbeitung zur Ermittlung von Merkwalen fur die automatische Klassifikation von Arrytmien.Un filtre passe-bande simple mais efficace est proposé pour le prétraitement des signaux ECG. Il est constitué de deux filtres triangulaires en parallèlle, implémentés de manière récursive. Son application au traitement de signaux ECG bruités montre que les variations de la ligne de base sont eliminées, que la composante fondamentale ainsi que les harmoniques du réseau sont supprimées, et que les artefacts sont considerablement atténues. Ce filtrage est necessaire comme pretraitement à l'extraction des caracteristiques pour la classification automatique des arythmies.
VLSI for pattern recognition and image processing
Signal Processing, 1986
Signal Processing, 1986
A framework supported by a set of tools for turning digital signal processing algorithms into cus... more A framework supported by a set of tools for turning digital signal processing algorithms into custom chips is proposed. The framework, called MOVAL, integrates analysis, layout synthesis and validation and is based on a structured top-down design methodology covering seven succinct abstraction levels: the behavioral, data representation, space/time, hardware, symbolic and geometric (mask) descriptions, and the chip. The top four levels efficiently cope with the implementation trade-offs and are all written in the same high level language, currently "C". As a result, the design can be modeled using a mixture of components defined at different abstraction levels. This allows an efficient mixed-mode multi-level validation. The hardware description is unambiguous and is the key to (semi-) automatic synthesis of the layout. Furthermore, it generates test vectors for the symbolic layout, the mask and, finally, the chip. The validation is done automatically, based on back substitution. As an example of the proposed design methodology, the crucial steps of the implementation of a fast Fourier cosine transform algorithm are described.
Preprocessing of electrocardiograms by digital techniques
Signal Processing, 1982
ABSTRACT
Automated ECG monitoring based on pattern recognition principle
Signal Processing, 1984
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Papers by adriaan Ligtenberg