ARTICLE Ba_IEEESMC-B_2008/IDIAP Recognizing Human Visual Focus of Attention from Head Pose in Meetings Ba, Silèye O. Odobez, Jean-Marc EXTERNAL http://publications.idiap.ch/attachments/papers/2008/Ba_IEEESMC-B_2008.pdf PUBLIC IEEE Transactions on Systems, Man, Cybernetics, Part-B Vol. 39 No. 1 16-34 2009 February 2009 We address the problem of recognizing the visual focus of attention (VFOA) of meeting participants based on their head pose. To this end, the head pose observations are modeled using a Gaussian Mixture Model (GMM) or a Hidden Markov Model (HMM) whose hidden states corresponds to the VFOA. The novelties of this work are threefold. First, contrary to previous studies on the topic, in our set-up, the potential VFOA of a person is not restricted to other participants only. It includes environmental targets as well (a table and a projection screen,',','), which increases the complexity of the task, with more VFOA targets spread in the pan as well as tilt gaze space. Second, we propose a geometric model to set the GMM or HMM parameters by exploiting results from cognitive science on saccadic eye motion, which allows the prediction of the head pose given a gaze target. Third, an unsupervised parameter adaptation step not using any labeled data is proposed which accounts for the specific gazing behaviour of each participant.