Jian Li

          School of Electronic Engineering and Computer Science
          Queen Mary University of London
          Mile End Road, London, E1 4NS. UK.

          Email: jianli@dcs.qmul.ac.uk



Updates:



From August 2007 to August 2010, I was a research assistant in School of Electronic Engineering and Computer Science, Queen Mary University of London. I worked with  Prof. Shaogang Gong and Dr. Tao Xiang on the BEWARE project, to develop computer vision solutions to enchance global situation awareness in wide area by analysing visual behaviours from multiple camera views. My research interests include behaviour profiling, scene context modelling, action recognition and behaviour retrieval.

Before joining Queen Mary University of London, I was a PhD student at University of Bristol. My PhD project was for developing models to estimate and fuse optical flow information from multi-modality cameras and study human vision perception for visual surveillance applications. I was awarded full scholarship from University of Bristol and General Dynamics for my PhD research.



Education:

Ph.D in Computer Vision and Experimental Psychology, University of Bristol, 2008
Supervisors: Dr. Chris Benton, Dr. Stavri Nikolov, Dr. Nick Scott-Samuel
Thesis: Fusing motion information with spatial structure for surveillance applications

M.Sc in Control Systems, Imperial College London, 2003
Supervisor: Dr. J.M.C. Clark
Dissertation: Data association for multiple target tracking

B.Eng in Automatic Control, Harbin Engineering University, 2002



Data Set:

The Computer Vision Group releases three videos monitoring crowded traffic scenes. To download, click here



Current Research:

Discriminative Topics Modelling for Action Feature Selection and Recognition

This paper presents a framework for recognising realistic human actions captured from unconstrained environments. The novelties of this work lie in three aspects. First, we propose a new action representation based on computing a rich set of descriptors from key point trajectories. Second, in order to cope with drastic changes in motion characteristics with and without camera movements, we develop an adaptive feature fusion method to combine different local motion descriptors for improving model robustness against feature noise and background clutters. Finally, we propose a novel Multi-Class Delta Latent Dirichlet Allocation model for feature selection. The most informative features in a high dimensional feature space are selected collaboratively, rather than independently as by existing feature selection methods. Extensive experiments on challenging public datasets demonstrate the effectiveness of the proposed framework.

M. Bregonzio, J. Li, S. Gong and T. Xiang, Discriminative Topics Modelling for Action Feature Selection and Recognition, in Proceedings of British Machine Vision Conference (BMVC), Aberystwyth, UK, 31st August - 3rd September, 2010.


Discovering Multi-Camera Behaviour Correlations for On-the-Fly Global Activity Prediction and Anomaly Detection

We propose a unified framework using Latent Dirichlet Allocation (LDA) for discovering behaviour global correlations over a distributed camera network. We explore LDA for categorising object motion patterns as local behaviours in each camera view before correlating these local behaviours globally over different physical locations in multi-camera views. In particular, a Temporal Order Sensitive
LDA (TOS-LDA) is formulated to discover behaviour global temporal correlations of different durations among all camera views simultaneously. In addition, a novel online global activity prediction method is proposed based on which global anomalies can be detected on the fly.

J. Li, S. Gong, T. Xiang, Discovering Multi-Camera Behaviour Correlations for On-the-Fly Global Activity Prediction and Anomaly Detection, IEEE International Workshop on Visual Surveillance, Kyoto, Japan, 3rd October, 2009.

Global Behaviour Inference using Probabilistic Latent Semantic Analysis

We present a novel framework for inferring global behaviour patterns through modelling behaviour correlations in a wide-area scene and detecting any anomaly in behaviours occurring both locally and globally. Specifically, we propose a semantic scene segmentation model to decompose a wide-area scene into regions where behaviours share similar characteristic and are represented as classes of video events bearing similar features. To model behavioural correlations globally, we investigate both a probabilistic Latent Semantic Analysis (pLSA) model and a two-stage hierarchical pLSA model for global behaviour inference and anomaly detection.

J. Li, S. Gong, T. Xiang, Global Behaviour Inference using Probabilistic Latent Semantic Analysis, in Proceedings of British Machine Vision Conference (BMVC), Leeds, UK, 1-4 September, 2008.

Scene Decomposition for Behaviour Correlation

In this work, we developed an approach for learning spatial context and correlational context for abnormal behaviour detection. Without employing tracking, low-level motion and shape features are extracted and clustered to represent local video events. An unsupervised spectral clustering is applied to determine the number of scene segments and perform decomposition. In each of the regions, representation for video events is further refined and global concurrence matrix is learned to perform abnormal behaviour detection.

J. Li, S. Gong and T. Xiang, Scene Segmentation for Behaviour Correlation, in Proceedings of European Conference on Computer Vision (ECCV), Marseille, France, 2008.


Previous Research:

Adaptive Summarisation of Surveillance Video Sequences

We describe our studies on summarising surveillance videos using optical flow information. The proposed method incorporates motion analysis into a video skimming scheme in which the playback speed is determined by the detectability of interesting motion behaviours according to prior information. A psycho-visual experiment was conducted to compare human performance and viewing strategy for summarised videos using standard video skimming techniques and a proposed motion-based adaptive summarisation technique.

J. Li, S. G. Nikolov, C. P. Benton, N. E. Scott-Samuel, Adaptive Summarisation of Surveillance Video Sequences, in the International Conference on Advanced Visual Surveillance Systems (AVSS), 5-7, London, UK, 5-7 September, 2007. 

Adaptive Multiscale Optical Flow Estimation

We present a novel adaptive multiscale scheme to estimate optical flow from image sequences. The scheme models estimation uncertainties which are used to reduce the influence of unreliable intermediate estimates on accuracy. The experimental results show that the proposed method provides more accurate estimates for both small and large motions than a standard multiscale scheme in which an increment is added to an intermediate estimate regardless of estimation certainty.

J. Li, C. P. Benton, S. G. Nikolov, N. E. Scott-Samuel, Adaptive Multiscale Optical Flow Estimation, in the International Conference on Image Processing (ICIP), San Antonio, Texas, USA, 16-19 September,  2007.

Motion-Based Video Fusion Using Optical Flow Information

Multi-sensor information fusion aims at extracting and combining useful information from different sensors. This work addresses the problem of estimating and visualising motion information from a pair of visible and infrared cameras, using an optical flow technique. Videos from cameras sensitive to visible light are rich in texture and colour information such that a moving target can readily be positioned. On the other hand, videos from infrared cameras provide extra information which cannot be detected in the visible-light spectrum. In this paper we introduce a stochastic rule for combining optical flow computed from two (or more) sources. We also propose a novel motion-contingent selection method for the fusion of the co-registered visible and infrared video sources.

J. Li, S. G. Nikolov, C. P. Benton, N. E. Scott-Samuel, Motion-Based Video Fusion using Optical Flow Information, in the 9th International Conference on Information Fusion (Fusion 2006), Florence, Italy, 10-13 July, 2006.

Reliable Real-Time Optical Flow Estimation for Surveillance Applications

We present a reliable real-time optical flow estimation framework which can be used in surveillance applications and video analysis. In normal imaging environments, reliability can be achieved by combining an extended optical flow constraint with a smoothing procedure and a masking procedure. In noisy environments, total least squares is adopted to ensure accuracy. The proposed system is able to recover up to 31 frames of dense optical flow per second using a Xeon 3.06GHz workstation, which makes it very useful in a range of surveillance systems that are based on standard PC hardware.

J. Li, S. G. Nikolov, N. E. Scott-Samuel, C. P. Benton, Reliable Real-Time Optical Flow Estimation for Surveillance Applications, in the Proceedings of the IEE Conference on Crime and Security: Imaging for Crime Detection and Prevention (ICDP), London, UK, 13-14 June, 2006.



Publications:

Journal Articles:

J. Li, S. Gong and T. Xiang, Learning Behavioural Context, accepted to International Journal of Computer Vision (IJCV), 2011

T. Hospedales, J. Li, S. Gong and T. Xiang, Identifying Rare and Subtle Behaviours: A weakly Supervised Joint Topic Model, to appear in IEEE Transactions on Pattern Analysis and Machine Intelligence (IEEE PAMI), 2011.

T. D. Dixon, S. G. Nikolov, J. J. Lewis, J. Li, E. F. Canga, J. M. Noyes, T. Troscianko, D. R. Bull, C. N. Canagarajah, Task-based scanpath assessment of multi-sensor video fusion in complex scenarios, Information Fusion, Vol. 11, Issue 1, page 51-65, 2010.


T. D. Dixon, S. G. Nikolov, J. Lewis, J. Li, E. F. Canga, J. M. Noyes, T. Troscianko, D. R. Bull, C. N. Canagarajah, Assessment of Fused Video Using Scanpaths: A Comparison of Data Analysis Methods, Spatial Vision, Volume 20, Number 5, pp. 437-466(30), 2007.


Conference Articles:

J. Li, T. M. Hospedales, S. Gong and T. Xiang, Learning Rare Behaviours, Asian Conference on Computer Vision (ACCV), Queenstown, New Zealand, 8-12 November, 2010.

M. Bregonzio, J. Li, S. Gong and T. Xiang, Discriminative Topics Modelling for Action Feature Selection and Recognition, in Proceedings of British Machine Vision Conference (BMVC), Aberystwyth, UK, 31st August - 3rd September, 2010.

J. Li, S. Gong, T. Xiang, Discovering Multi-Camera Behaviour Correlations for On-the-Fly Global Activity Prediction and Anomaly Detection, IEEE International Workshop on Visual Surveillance, Kyoto, Japan, 3rd October, 2009.

J. Li, S. Gong, T. Xiang, Scene Segmentation for Behaviour Correlation, in Proceedings of European Conference on Computer Vision (ECCV), Marseille, France, 12-18 October, 2008. 

J. Li, S. Gong, T. Xiang, Global Behaviour Inference using Probabilistic Latent Semantic Analysis, in Proceedings of British Machine Vision Conference (BMVC), Leeds, UK, 1-4 September, 2008.

J. Li, C. P. Benton, S. G. Nikolov, N. E. Scott-Samuel, Adaptive Multiscale Optical Flow Estimation, in the International Conference on Image Processing (ICIP), San Antonio, Texas, USA, 16-19 September,  2007.

J. Li, S. G. Nikolov, C. P. Benton, N. E. Scott-Samuel, Adaptive Summarisation of Surveillance Video Sequences, in the International Conference on Advanced Visual Surveillance Systems (AVSS), 5-7, London, UK, 5-7 September, 2007. 
 
T. Dixon, S. G. Nikolov, J. Li, E. F. Canga, J. J. Lewis, T. Troscianko, J. Noyes, C. N. Canagarajah, D. R. Bull, Scanpath Assessment of Visible and Infrared Side-by-Side and Fused Video Displays, in the Proceedings of the 10th International Conference on Information Fusion, (Fusion 2007), Quebec City, Canada, 9-12 July 2007.

J. Li, S. G. Nikolov, C. P. Benton, N. E. Scott-Samuel, Motion-Based Video Fusion using Optical Flow Information, in the 9th International Conference on Information Fusion (Fusion 2006), Florence, Italy, 10-13 July, 2006.
 
J. Li, S. G. Nikolov, N. E. Scott-Samuel, C. P. Benton, Reliable Real-Time Optical Flow Estimation for Surveillance Applications, in the Proceedings of the IEE Conference on Crime and Security: Imaging for Crime Detection and Prevention (ICDP), London, UK, 13-14 June, 2006.
 
T. D. Dixon, S. G. Nikolov, J. J. Lewis, J. Li, E. F. Canga, J. Noyes, T. Troscianko, D. R. Bull, C. N. Canagarajah, Scanpath Analysis of Fused Multi-Sensor Images with Luminance Change: A Pilot Study, in the 9th International Conference on Information Fusion (Fusion 2006), Florence, Italy, 10-13 July, 2006. 
 
L. Mihaylova, A. Loza, S. G. Nikolov, J. J. Lewis, E.-F. Canga, J. Li, C. N. Canagarajah and D. R. Bull, The Influence of Multi-Sensor Video Fusion on Object Tracking Using a Particle Filter, in the Proceedings of the 2nd Workshop Multiple Sensor Data Fusion: Trends, Solutions, Applications, Dresden, Germany, 2-6 October, 2006.
 
T. D. Dixon, S. G. Nikolov, J. Lewis, J. Li, E. F. Canga, J. M. Noyes, T. Troscianko, D. R. Bull, C. N. Canagarajah, Multi-Sensor Fused Video Assessment Using Scanpath Analysis, in the Proceedings of the Biologically Inspired Information Fusion Workshop, Sussex, pp 14-19, August, 2006.


Technical Reports:

J. Li, S. G. Nikolov, C. P. Benton, N. E. Scott-Samuel, Multi-Sensor Motion Computation, Analysis and Fusion, University of Bristol Technical Report, March 2006.

J. Li, S. G. Nikolov, C. P. Benton, N. E. Scott-Samuel, Video Summarisation Through Fusion of Motion and Spatial Information. University of Bristol Technical Report, September 2006.

L. Mihaylova, A. Loza, S. G. Nikolov, J. J. Lewis, J. Li, et al, Object Tracking in Multi-Sensor Video, University of Bristol Technical Report, March 2006.

S. G. Nikolov, J. Li, J. J. Lewis, et al, Spatio-Temporal Video Fusion, University of Bristol Technical Report, September 2006.

J. J. Lewis, S. G. Nikolov, J. Li, et al, Techniques for Multi-Sensor Video Fusion, University of Bristol Technical Report, September 2006.

J. J. Lewis, S. G. Nikolov, J. Li et al, The Eden Project Multi-Sensor Data Set, University of Bristol Technical Report, September 2005.