@patent{BlaRomSchTor04, title = {Pattern detection methods and systems and face detection methods and systems}, author = {Blake, A. and Romdhani, S. and Sch{\"o}lkopf, B. and Torr, P. H. S.}, howpublished = {United States Patent, No 6804391}, month = oct, year = {2004}, note = {(expired)}, doi = {}, month_numeric = {10} }