X-MOVIE: Transmission and Presentation of Digital Movies under X

We describe a system for storing, transmitting and presenting digital films in a computer network. The hardware used in the system is standard hardware, as found in typical workstations today; no special hardware is required. The movies are shown in a window of the X Window System. This allows full integration with the classical components of computer applications such as text, color graphics, menues and icons. The X-MOVIE system is based on color lookup table technology. We present a new algorithm for the gradual adaptation of the color lookup table during the presentation of the film

Automatic text segmentation and text recognition for video indexing

Efficient indexing and retrieval of digital video is an important function of video databases. One powerful index for retrieval is the text appearing in them. It enables content-based browsing. We present our methods for automatic seg-mentation of text in digital videos. The output is directly passed to a standard OCR software package in order to translate the segmented text into ASCII. The algorithms we propose make use of typical characteristics of text in videos in order to enable and enhance segmentation performance. Especially the inter-frame dependencies of the characters provide new possibilities for their refinement. Then, a straightforward indexing and retrieval scheme is intro-duced. It is used in the experiments to demonstrate that the proposed text segmentation algorithms together with exist-ing text recognition algorithms are suitable for indexing and retrieval of relevant video sequences in and from a video database. Our experimental results are very encouraging and suggest that these algorithms can be used in video retrieval applications as well as to recognize higher seman-tics in videos

Efficient Implementation of Estelle Specifications

Efficient implementation of communication software is of critical importance for high-speed networks. We analyze performance bottlenecks in existing implementations and propose two techniques for improvements: The first exploits parallelism not only in the actions of the FSMs, but also in the runtime system of the protocol stack. The second integrates adjacent layers leading to considerable savings in inter-layer interface handling and in the number of transitions occurring in the FSMs. Both techniques are discussed in the context of OSI upper layers, and are based on protocol specification in Estelle

Effiziente Verarbeitung von multimedialen Datenströmen in Window-Systemen

Fensterorientierte Oberflaechen haben sich auf Workstations aller Leistungsklassen durchgesetzt. Deshalb liegt es nahe, Multimedia-Anwendungen in solche Oberflaechen zu integrieren. Dieser Artikel gibt zunaechst eine Uebersicht ueber die verschiedenen technischen Moeglichkeiten zur Integration von Multimedia-Datenstroemen in ein Fenstersystem; die Vor- und Nachteile der einzelnen Ansaetze werden gegenuebergestellt. Waehrend Loesungen mit Hardware-Unterstuetzung im allgemeinen schneller sind, sind reine Software-Implementierungen flexibler und portabler. Als ein Beispiel fuer eine Software-Loesung werden Architektur, Implementierung und Leistungsanalyse eines netzwerkfaehigen Filmsystems fuer das X-Window-System ausfuehrlich diskutiert. Es zeigt sich, dass die Uebertragung und Darstellung von digitalen Filmen auf modernen Workstations in Hochgeschwindigkeitsnetzen ohne spezielle Hardware in Realzeit moeglich ist. Außerdem werden neue Ansaetze zur Gestaltung der Mensch-Maschine-Schnittstelle mit multimedialen Komponenten vorgestellt

MCAM: An Application Layer Protocol for Movie Control, Access, and Management

Most of the recent work on distributed multimedia systems has concentrated on the transmission, synchronization and operating system support for continuous media data streams. We consider the integrated control of remote multimedia devices, such as cameras, speakers and microphones, to be an important part of a distributed multimedia system. In this paper we describe MCAM, an application layer architecture, service and protocol for Movie Control, Access, and Management in a computer network. The OSI Reference Model is our framework. We present the protocol data units and the Finite State Machine for our application protocol and outline the automatic generation of the implementation code for layer 7 from our formal specification. MCAM allows complete and integrated control of movie data streams and devices in a heterogeneous multimedia network

Seamless Integration of Group Communication into an Adaptive Online Exercise System

Distance learners in traditional online exercise and tutoring systems often get stuck with questions for which they need the help of a tutor or colleague. Learning alone can also be frustrating. In our Communication And Tutoring System CATS we have integrated the possibility to dial up a tutor and/or to setup an immediate group communication with other distance learners using Internet videoconferencing technology. To find the appropriate partner, we have implemented a measurement algorithm that keeps track of the performance level of a learner by measuring the percentage of correct answers at the current level, the reliability with which the learner answers the questions and the time he/she takes. From these measures we derive a unified performance parameter that controls the presentation of the next set of questions. These are then generated dynamically by the exercise applet. The CATS system automatically selects the most appropriate communica-tion partner(s) bas! ed on the exercises the learners are currently working on, and on their skill levels. We motivate this approach from a pedagogical point of view and present the architecture and implementation of the CATS system

MHEG: An Interchange Format for Interactive Multimedia Presentations

This paper surveys the upcoming MHEG standard, as under development by the Multimedia Hypermedia Experts Group of ISO. It's scope is to define a system-independent encoding of the structure information which can be used for storing, exchanging, and executing of multimedia presentations in final form. We use a running example to describe the building blocks of an MHEG encoded presentation. To contribute our experience using MHEG in a networked multimedia kiosk environment, we present a complete MHEG run-time environment

Enhancing curvature scale space features for robust shape classification

The curvature scale space (CSS) technique, which is also part of the MPEG-7 standard, is a robust method to describe complex shapes. The central idea is to analyze the curvature of a shape and derive features from inflection points. A major drawback of the CSS method is its poor representation of convex segments: Convex objects cannot be represented at all due to missing inflection points. We have extended the CSS approach to generate feature points for concave and convex segments of a shape. This generic approach is applicable to arbitrary objects. In the experimental results, we evaluate as a comprehensive example the automatic recognition of characters in images and videos