Joseph O'Sullivan's research interests include information theory, information-theoretic imaging, recognition theory and systems, CT imaging, optical imaging, information hiding, and hyperspectral imaging. O'Sullivan was chair of the St. Louis Section of the IEEE in 1994 and was awarded an IEEE Third Millennium Medal. He is also a Fellow of the IEEE and a member of Eta Kappa Nu, SPIE, SIAM, and AAAS.
In 1986, Professor O'Sullivan joined the faculty in the Department of Electrical Engineering at Washington University in St. Louis (WashU). He was the Director of the Electronic Systems and Signals Research Laboratory (ESSRL) from 1998 to 2007. Today, O'Sullivan directs the Imaging Science and Engineering certificate program.
O'Sullivan was Chair of the Faculty Senate Council and Faculty Representative to the Board of Trustees at WashU from 2002 to 2004. He was the Publications Editor for the IEEE Transactions on Information Theory from 1992 to 1995, an Associate Editor for Detection and Estimation, and was a Guest Associate Editor for the 2000 Special Issue on Information Theoretic Imaging. In 1999, he was co-chair of the Information Theory Workshop on Detection, Estimation, Classification, and Imaging.
In 2003, O'Sullivan was the local arrangements chair for the IEEE 2003 Statistical Signal Processing Workshop. He was also co-chair of the IEEE 2006 International Symposium on Information Theory.