24,129 research outputs found
Physical simulation for monocular 3D model based tracking
The problem of model-based object tracking in three dimensions is addressed. Most previous work on tracking assumes simple motion models, and consequently tracking typically fails in a variety of situations. Our insight is that incorporating physics models of object behaviour improves tracking performance in these cases. In particular it allows us to handle tracking in the face of rigid body interactions where there is also occlusion and fast object motion. We show how to incorporate rigid body physics simulation into a particle filter. We present two methods for this based on pose and force noise. The improvements are tested on four videos of a robot pushing an object, and results indicate that our approach performs considerably better than a plain particle filter tracker, with the force noise method producing the best results over the range of test videos
Signature of a Cosmic String Wake at
In this paper, we describe the results of N-body simulation runs, which
include a cosmic string wake of tension on top of the
usual fluctuations. To obtain a higher resolution of the wake in
the simulations compared to previous work, we insert the effects of the string
wake at a lower redshift and perform the simulations in a smaller volume. A
curvelet analysis of the wake and no-wake maps is applied, indicating that the
presence of a wake can be extracted at a three-sigma confidence level from maps
of the two-dimensional dark matter projection down to a redshift of .Comment: 8 pages, 6 figures; We have improved the analysis and results. The
text now agrees with the published versio
Particle detection and tracking in fluorescence time-lapse imaging: a contrario approach
This paper proposes a probabilistic approach for the detection and the
tracking of particles in fluorescent time-lapse imaging. In the presence of a
very noised and poor-quality data, particles and trajectories can be
characterized by an a contrario model, that estimates the probability of
observing the structures of interest in random data. This approach, first
introduced in the modeling of human visual perception and then successfully
applied in many image processing tasks, leads to algorithms that neither
require a previous learning stage, nor a tedious parameter tuning and are very
robust to noise. Comparative evaluations against a well-established baseline
show that the proposed approach outperforms the state of the art.Comment: Published in Journal of Machine Vision and Application
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