Information as found and viewable in the Telephonebook
Room:
ZI 2029
Telephone:
+31 53 489 2836
News
Mar 2012: An interview with Ellen Giebels, Matthijs Noordzij, Elze Ufkes, Dirk Heylen and me about our joint work on the detection of deceit appeared in the UT-Nieuws. It can be read online on pages 26 and 27.
Feb 2012: With Tobias Heffelaar (Noldus) and Jordi Bieger (Vicar Vision), I'm organizing a special session on "Technical support for analysis of human error in task performance" at Measuring Behaviour 2012, Utrecht, August 28-31.
Feb 2012: Iwan de Kok, Dirk Heylen and me introduced a novel way of learning computational models for the synthesis of social behavior from corpora. Our approach, Iterative Perceptual Learning (IPL), explicitly takes into account how the behavior is perceived by humans, and iteratively refines the models based on these ratings. A technical report can be downloaded.
Feb 2012: My paper on face naming in online social networks will appear in the June edition of Pattern Recognition. It is already online.
Jan 2012: I'm looking for a motived student for a challenging master's assignment on automatically estimating a person's body sizes using webcam images. The assignment will be carried out in the context of an inspiring project. Contact me if you're interested!
Jan 2012: With Hayley Hung (Uva) and Janienke Sturm (TU/e), I'm organizing a workshop on "Measuring behaviour in open spaces" at Measuring Behaviour 2012, Utrecht, August 28-31.
Jan 2012: I've received the "most cited paper award 2012" for the Image and Vision journal for my survey on vision-based human action recognition.
Upcoming workshops/conferences and new journal
International Conference on Autonomous Agents and Multiagent Systems (AAMAS2012) Website Valencia, Spain, June 4-8 2012
International Conference on Computer Vision and Pattern Recognition (CVPR2012) Website Providence, Rhode Island, USA, June 16-21, 2012
International Conference on Multimodal Interaction (ICMI2012) Website Santa Monica, California, USA, October 22-26, 2012
International Conference on Distributed Smart Cameras (ICDSC2012) Website Hong Kong, Oct 30 - Nov 2 2012
Workshop on Multimodal Corpora: How Should Multimodal Corpora Deal With The Situation? Website - In conjunction with the International Conference on Language Resources and Evaluation (LREC) Istanbul, Turkey, May 21-27, 2012
International Conference on Informatics, Electronics & Vision (ICIEV2012) Website Dhaka, Bangladesh, May 18/19, 2012
International Journal of Computer Vision & Signal Processing (IJCVSP) Website - An open access journal on computer vision and signal processing
Currently, I'm a postdoctoral researcher working on computer vision and human behavior analysis. In 2009, I was a visiting researcher at the Delft University of Technology, working on the PetaMedia project. In 2010, I spent two months at Stanford University. My PhD thesis "Discriminative Vision-Based Recovery and Recognition of Human Motion", can be found online here.
Research
Human motion analysis
My research into human motion analysis focusses mainly on the use of discriminative approaches. In example-based work, the choice of image descriptor is important, and we investigated how well different silhouette shape descriptors performed on a synthetic data set. Dataset and software are available, please contact me. Published in FG 2006.
For example-based human pose recovery, we performed extensive evaluations on the HumanEva dataset with a variant of HOG as image descriptor. We studied how the recovery accuracy was influenced by different persons, actions and number of views. Dataset and software are available, please contact me. Some videos: divx, xvid, mpeg. Published in CVPR-EHuM 2007.
We used a set of synthetically generated body part templates to detect humans and simultaneously estimate their poses in 2D. Since we match at the body part level, but estimate joint locations for the whole body, we can deal with occlusion. Such an approach is feasible when a limited motion domain is considered. Here, we show results on Walking and Jogging movements. Video: xvid. Published in AMDO 2008.
To recognize human actions, we introduced a framework where pairwise discriminative functions between two actions were used. Common spatial patterns (CSP) was used to maximize the difference in variance between the actions. Such a framework can be learned efficiently, and evaluation of the functions can be done in real-time with a small number of training sequences. We evaluated our approach on the Weizmann human action dataset and obtained competitive results. Published in FG 2008.
Backchannels are a common type of listener responses. We investigated algorithms that automatically place backchannels while processing the speech of a speaker, and evaluated these using a corpus, and using human perception. Stimuli, code and results are available, please contact me. Video: xvid. Published in IVA 2011, IVA 2010, Interspeech 2011 and Interspeech 2010.
Research has revealed high accuracy in the perception of gaze in dyadic (sender-receiver) situations. Triadic situations differ from these in that an observer has to report where a sender is looking, not relative to himself. We looked at the accuracy of perception in these situations. Published in ACM TAP.
Face naming in social networks
Social networks can contain very large numbers of photos, often portraying the users of the network. We focus on naming detected faces in photos in a scalable way by exploiting the social network of the user. Published in FG2011 and Pattern Recognition.
Perception of affect
The body can display many forms of affect. However, much research that investigates the role between pose and affect suffers from methodological issues. We looked into the factor of stimulus realism. Stimuli, code and results are available, please contact me. Published in ACII 2007.
Multimodal human-computer interaction
The Virtual Dancer is an interactive application that allows users to dance together with an animated dancer. A camera and dance mat are used to observe the user's moves. Showcase.
The Distributed Virtual Meeting Room allows to have real-time distributed meetings, and can be used for offline meeting visualization. Additional information such as current speaker, dominance level and agenda progress can be shown. Showcase.
Within the ICIS-CHIM project, a multimodal system has been developed to facilitate communication between rescue workers at distributed locations.
Other projects
Tetris-with-your-body. Play the game of Tetris using some hand gestures. A camera observes the body and hands, and translates the movements to game actions.
Jump-and-run. A demo where players can control a running character in a game using their body movements. By jumping, ducking and moving left and right, obstacles can be avoided and bonuses collected.
