Yi Li Researcher, Computer Vision Group, NICTA and ANU yi.li AT cecs DOT anu DOT edu DOT au |
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Education · Aug 2004 – present Computer Vision Lab, University of Maryland, College Park Advised by Prof. Yiannis Aloimonos and Dr. Cornelia Fermuller · Aug 2001 - Oct 2004 · Aug 1998 - Oct 2001 South China University of Technology, Guangzhou · Human Movement Analysis · Cognitive Robotics; · Assessing Human Action for Disease Diagnosis · Social Signal Processing for Social Intelligence; · Computer Vision and Machine Learning · Visual Perception and Optical Illusions; · Action and Object Recognition; · Sparseness Recovery;
· Jan 2008, Future Faculty Fellow, A.
James Clark ·
2nd place, 1st Semantic Robot Vision
Challenge (sponsored by NSF), AAAI2007, · Best student paper, 10th International Conference on Frontiers in Handwriting Recognition, 2006. |
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A. Human Movement Analysis Human movement is a window into nervous system functions.
One of my goals is to work towards measuring and interpreting human motion
capture (MoCap) data
for improving the functionalities that facilitate the robot-human interaction
in a social context, and developing tools for disease diagnosis and
rehabilitation related to aging and various disorders or conditions
that exhibit themselves through movement. |
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A.1. Movement Synergies for Cognitive Robots We decompose motion capture (MoCap) sequences into synergies (smooth and short basis functions) along with the times at which they are “activated” for each joint. The result will provide the effective building blocks for robotics research, such as generating natural humanoid body movements. (read more...)
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A.2. Assessing
Human Health
My research focuses on measuring human action, understanding its coordination characteristic, and further developing optimal diagnostic and intervention tools for populations with atypical movement patterns.
I have worked on Parkinson’s disease, and in the future, I plan to work on early diagnosis of developmental diseases on the basis of movement (e.g., Autism).
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A.3. Coordinated
Actions Coordination has gained more attention than others in cognitive studies because all species have complex coordination behaviors for defensive, reproductive or hunting. Suggested by Prof. Fadiga and Dr.Alessandro D'Ausilio, we proposed to use Granger Causality as a tool to study the coordinated actions performed by at least two units. If one action causes the other, then knowledge (history) of the first action should help predict future values of the latter. We successfully applied Granger Causality to the kinematic data in a chamber orchestra to test the interaction among players and between conductors and players. (joint work with Prof. Fadiga and Dr.Alessandro D'Ausilio , read more...) |
B. Computer Vision and Machine Learning for Cognitive Systems A cognitive vision system is the embodiment of a series of principles that views cognition as the starting point of any computational vision algorithm. As said by Aristotle, humans are social animals. Thus, cognitive vision systems should be suited for assisting social interaction. I am working on providing tools for analyzing human actions in visual space and motoric space and semantic object recognition. In parallel, I am interested in active perception and early vision. |
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B.1. Visual Illusions The gray squares have the same intensity value. Why do we think they are different? What is the underlying mathematics which tells us how to actively sample and reconstruct a real-world scene? I proposed to use the new theory of compressive sensing as the model. The reconstruction error can explain many well-known lightness illusions, e.g., the dilemma between contrast and assimilation. (read more...) |
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B.2.
Action Key Pose Extraction for Human-Robot-Interaction Not all poses are created equal. We model the key poses as the discontinuities in the second order derivatives of the latent variables in the reduced visual space which we obtain using the Gaussian Process Dynamical Models (GPDM). Experiments demonstrate that the extracted key poses facilitate the human action analysis and improve the action recognition rate significantly by reducing the uncharacteristic poses.(read more...) |
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B.3. Semantic Object Recognition for Intelligent Service Robots Intelligent service robots must search, identify and further interact with objects just from their names like humans do. We implement a prototype system in the Semantic Robot Vision Challenge on a mobile platform that parses the large amount of the semantic information available online, automatically searches image examples of those objects and learns visual models, and actively segments and locates the objects using a quad camera system on a pan-tilt-unit in a previous unknown environment. (read more...) |
II. Past Research |
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(Joint work with Prof. David Jacobs) |
(Joint work with Xiaodong Yu) |
Script-Independent Text Line Segmentation IEEE Trans on PAMI 08 (bibtex) (dataset) (Joint work with Dr. David Doermann, Dr. Yefeng Zheng, and Dr. Stefan Jaeger) |
ECCV'08 (bibtex), Pattern Recog 08 (bibtex) (Joint work with Guangyu Zhu) |
Detect
and Locate Low Contrast Character IEEE Trans on PAMI 04 (bibtex) (joint work with Prof. Zhiyan Wang) |
(joint work with K. Bitsakos, C. Fermuller and Y.
Aloimonos) |