Vol. 42 No. 2 March, 1998   Preface   


Preface 


The steady advances in computing technology for over a decade have brought 
about a revolution in the way we use computers in our everyday life. The 
progress to date has also succeeded in modernizing businesses and solving 
problems that were previously intractable. The advances in multimedia 
systems, however, promise an even greater change in the personal usage of 
computers. The ability to deliver and process audio and video with devices 
that can reside in a person's home or office will enhance the way we 
conduct business, obtain education, and entertain ourselves. While the 
promise of multimedia technology has been evident for quite some time, 
today we are much wiser about the barriers that have to be overcome for 
successful deployment of multimedia applications.

Considering how a multimedia application is brought to a user in the office 
or at home, one realizes that multimedia applications place many 
requirements and restrictions on the underlying technologies, from 
databases and file systems to signal processing and networking. Multimedia 
files are large, and a huge amount of data has to be transported (most 
often in real time) from remote servers to the end users. Various 
technologies are taking advantage of the existing wiring infrastructure and 
have brought us to a point where a substantial amount of data, audio, and 
video can be delivered to users. The ability to retrieve and process video 
entails not only real-time requirements but also requirements for storing, 
managing, and searching huge amounts of data. 

In this issue of the IBM Journal of Research and Development, we present 
some of the important ideas in multimedia and major efforts undertaken at 
IBM. We have collected papers that describe some of the major IBM projects, 
not only in the laboratories but in the field as well. 

The introductory paper, by Flynn and Tetzlaff, describes various terms and 
basic concepts in multimedia and provides a survey of various types of 
multimedia applications. The authors also review the technologies and 
architectures of systems for deploying such applications. 

In the next paper, by Dan et al., we take a fresh look at the progress (or 
lack of it) in multimedia and present a critical editorial perspective. We 
sketch the history of evolution in multimedia and present the major 
challenges that have to be addressed for successful deployment of 
multimedia-based applications. 

The paper by Haskin provides an overview of a significant effort on file 
systems for storage and real-time retrieval of large multimedia files. 
Tiger Shark addresses the requirements for large-scale multimedia as well 
as nonmultimedia applications, such as scientific computing and network 
servers. The paper describes the implementation of the file system and also 
presents experience in the use of Tiger Shark in real environments (field 
trials). 

In their paper, Sanuki and Asakawa describe the end-to-end architecture of 
an operational video-on-demand system deployed in Japan. The system is 
scalable to a large number of users and delivers video streams encoded in 
MPEG-2 over an HFC (hybrid fiber-coax) interconnection system. 

The paper by Kumar describes a proposal for an alternative architecture for 
video servers accommodating a large user population. In his approach, the 
author uses dedicated hardware for video delivery that is directly attached 
to the network, and the video information is stored in the form of network 
packets. This results in a server that avoids the processing and I/O 
bottleneck caused in traditional architectures by the protocol and file-
system overheads. 

One of the most important problems in multimedia technologies is obtaining 
information from large databases. The tremendous amount of data required in 
images and video streams has resulted in databases that are larger than 
traditional ones by several orders of magnitude. It is imperative to 
develop methodologies that allow us to "search" such databases on the basis 
of content information, in a simple, concise, and efficient fashion; this 
presents significant challenges, when one considers the available 
technology for databases. The following two papers address exactly this 
problem in the context of video and images, respectively. 

The paper by Bolle et al. describes a framework for viewing and searching 
video in such databases, while the paper by Castelli et al. describes a 
framework for searching images by means of some user-specified content 
description. 

The paper by Willebeek-LeMair et al. describes a solution for providing 
high-quality audio and video to users over low-bit-rate connections. The 
solution is Web-based and was demonstrated at the 1996 Summer Olympics. 

The final paper, by Bisdikian et al., describes a prototype Web-based 
teleconferencing system that enables collaborative work through audio and 
data conferences among users with heterogeneous systems. The audio is 
carried over the telephone network, while the data is carried over the 
Internet. Therefore, a key feature of this solution is that the clients do 
not require any special hardware or software. 

We are indebted to the authors, who spent a great deal of time to write the 
papers presented in this issue of the IBM Journal of Research and 
Development. We are all proud of this issue, which reflects the significant 
effort of the people in the IBM Corporation to enable multimedia technology 
for users in business and home environments. They have played an important 
role in a technology that is expected to significantly influence a wide 
range of activities. 

Asit Dan 
Stuart Feldman 
Dimitrios Serpanos 

Guest Editors