Dennis Koelma received the M.Sc. and Ph.D. degrees in computer science from the University of Amsterdam in 1989 and 1996, respectively. The subject of his thesis is "A software environment for image interpretation". Currently, he is working on Impala/Horus : a software architecture for doing research in accessing the content of digital images and video. His research interests include image and video processing, software architectures, parallel programming, databases, graphical user interfaces, and visual information systems.