Abstract
With the recent developments in multimedia and telecommunication technologies, content-based information is becoming increasingly important for various areas such as digital libraries, interactive video and multimedia publishing. Multimedia data refers to simple structured data (such as numbers and short strings), large unstructured data (such as text documents, images, audio and video data) and complex structured data (such as maps, graphs, charts and tables). In this article, we briefly address content-based retrieval and the issues of representation, storage and retrieval of multimedia objects in digital libraries. We then very briefly identify some open areas of research.