Prof. Gerald Schaefer
Loughborough University, UK
Content-based image retrieval, which is based on the principle of deriving visual similarity based on extracted image features, can be useful, especially since most images are unannotated. However, while almost all images are stored in compressed form (most in JPEG format), the vast majority of CBIR algorithms operate in the (uncompressed) pixel domain. This not only leads to a computational overhead for feature calculation, image compression can also lead to a drop of retrieval accuracy, in particular at extreme compression rates. In my talk, I will present efficient and effective CBIR techniques that operate directly in the JPEG compressed domain, hence not requiring full decompression for feature extraction. In particular, I will show how CBIR features can be extracted from DCT coefficients, from differentially coded DC data, and from tuned information contained in the JPEG headers, while yielding good retrieval performance.
Biography
Gerald Schaefer gained his PhD in Computer Vision from the University of East Anglia. He worked at the Colour & Imaging Institute, University of Derby (1997-1999), in the School of Information Systems, University of East Anglia (2000-2001), in the School of Computing and Informatics at Nottingham Trent University (2001-2006), and in the School of Engineering and Applied Science at Aston University (2006-2009) before joining the Department of Computer Science at Loughborough University.
His research interests are mainly in the areas of colour image analysis, image retrieval, physics-based vision, medical imaging, and computational intelligence. He has published extensively in these areas with a total publication count exceeding 400. He is/was a member of the editorial board of more than 20 international journals, has reviewed for over 120 journals and served on the programme committee of more than 350 conferences. He has been invited as keynote or tutorial speaker to numerous conferences, is the organiser of various international workshops and special sessions at conferences, and the editor of several books, conference proceedings and special journal issues.