Abstract
Traditional databases use simple data types chiefly numbers and strings—to represent information such as payroll records or scientific data. Queries commonly take the form of relational calculus or relational algebra expressions and the results require little more than a textual terminal for presentation. The natural successor to a traditional database is the Multimedia Information System which also uses richer data types—images, text, sound and so on—to describe some application domain. This calls for more advanced technologies such as graphical workstations for data creation and presentation, high-bandwidth networks for fast access to distributed data and large repositories for the storage of objects. These technologies are now widely available.
Ideally, queries put to a Multimedia Information System should refer to the content of stored objects—content retrieval—and results should be able to contain complex as well as simple data types. Manual entry of content descriptions is time-consuming, error-prone and subjective; a better approach is to draw on the emerging fields of image interpretation, text interpretation, speech interpretation and knowledge representation to provide automatic content retrieval.
This article serves as an introduction to Multimedia Information Systems and related fields and describes in detail a pilot system with automatic content retrieval built by the Multimedia Group at Manchester University.