Improved illumination-invariant descriptors for robust colour object recognition. - Robert J. O'Callaghan; David R. Bull (ICASSP, 2002)

A scale invariant distance measure for texture retrieval. - Robert J. O'Callaghan; David R. Bull (ICIP (1), 2002)

Video Retrieval Using Global Features in Keyframes. - Marcus Jerome Pickering; Daniel Heesch; Stefan M. Rüger; Robert J. O'Callaghan; David R. Bull (TREC, 2002)

Combined morphological-spectral unsupervised image segmentation. - Robert J. O'Callaghan; David R. Bull (IEEE Trans. Image Process., 2005)

Pixel- and region-based image fusion with complex wavelets. - John Joseph Lewis; Robert J. O'Callaghan; Stavri G. Nikolov; David R. Bull; Cedric Nishan Canagarajah (Inf. Fusion, 2007)