5 research outputs found
An advanced Bayesian model for the visual tracking of multiple interacting objects
Visual tracking of multiple objects is a key component of many visual-based systems. While there are reliable
algorithms for tracking a single object in constrained scenarios, the object tracking is still a challenge in
uncontrolled situations involving multiple interacting objects that have a complex dynamics. In this article, a novel
Bayesian model for tracking multiple interacting objects in unrestricted situations is proposed. This is accomplished
by means of an advanced object dynamic model that predicts possible interactive behaviors, which in turn depend
on the inference of potential events of object occlusion. The proposed tracking model can also handle false and
missing detections that are typical from visual object detectors operating in uncontrolled scenarios. On the other
hand, a Rao-Blackwellization technique has been used to improve the accuracy of the estimated object trajectories,
which is a fundamental aspect in the tracking of multiple objects due to its high dimensionality. Excellent results
have been obtained using a publicly available database, proving the efficiency of the proposed approach
SAVASA project @ TRECVID 2012: interactive surveillance event detection
In this paper we describe our participation in the interactive surveillance event detection task at TRECVid 2012. The system we developed was comprised of individual classifiers brought together behind a simple video search interface that enabled users to select relevant segments based on down~sampled animated gifs. Two types of user -- `experts' and `end users' -- performed the evaluations. Due to time constraints we focussed on three events -- ObjectPut, PersonRuns and Pointing -- and two of the five available cameras (1 and 3). Results from the interactive runs as well as discussion of the performance of the underlying retrospective classifiers are presented
On-road visual vehicle tracking using Markov chain Monte Carlo with metropolis sampling
In this study, a method for vehicle tracking through video analysis based on Markov chain Monte Carlo (MCMC) particle filtering with metropolis sampling is proposed. The method handles multiple targets with low computational requirements and is, therefore, ideally suited for advanced-driver assistance systems that involve real-time operation. The method exploits the removed perspective domain given by inverse perspective mapping (IPM) to define a fast and efficient likelihood model. Additionally, the method encompasses an interaction model using Markov Random Fields (MRF) that allows treatment of dependencies between the motions of targets. The proposed method is tested in highway sequences and compared to state-of-the-art methods for vehicle tracking, i.e., independent target tracking with Kalman filtering (KF) and joint tracking with particle filtering. The results showed fewer tracking failures using the proposed method
Advanced background modeling with RGB-D sensors through classifiers combination and inter-frame foreground prediction
An innovative background modeling technique that is able to accurately segment foreground regions in RGB-D imagery (RGB plus depth) has been presented in this paper. The technique is based on a Bayesian framework that efficiently fuses different sources of information to segment the foreground. In particular, the final segmentation is obtained by considering a prediction of the foreground regions, carried out by a novel Bayesian Network with a depth-based dynamic model, and, by considering two independent depth and color-based mixture of Gaussians background models. The efficient Bayesian combination of all these data reduces the noise and uncertainties introduced by the color and depth features and the corresponding models. As a result, more compact segmentations, and refined foreground object silhouettes are obtained. Experimental results with different databases suggest that the proposed technique outperforms existing state-of-the-art algorithms