Head pose tracking and focus of attention recognition algorithms in meeting rooms

Abstract

The paper presents an evaluation of both head pose and visual focus of attention (VFOA) estimation algorithms in a meeting room environment. Head orientation is estimated using a Rao-Blackwellized mixed state particle filter to achieve joint head localization and pose estimation. The output of this tracker is exploited in an Hidden Markov Model (HMM) to estimate people's VFOA. Contrarily to previous studies on the topic, in our set-up, the potential VFOA of people is not restricted to other meeting participants only, but includes environmental targets (table, slide screen), which renders the task more difficult due to more ambiguity between VFOA target directions. By relying on a corpus of 8 meetings of 8 minutes on average featuring 4 persons involved in the discussion of statements projected on a slide screen, and for which head orientation ground truth was obtained using magnetic sensor devices, we thoroughly assess the performance of the above algorithms, demonstrating the validity of our approaches and pointing out to further research directions. © Springer-Verlag Berlin Heidelberg 2007.