17 research outputs found
Long Range Automated Persistent Surveillance
This dissertation addresses long range automated persistent surveillance with focus on three topics: sensor planning, size preserving tracking, and high magnification imaging.
field of view should be reserved so that camera handoff can be executed successfully before the object of interest becomes unidentifiable or untraceable. We design a sensor planning algorithm that not only maximizes coverage but also ensures uniform and sufficient overlapped camera’s field of view for an optimal handoff success rate. This algorithm works for environments with multiple dynamic targets using different types of cameras. Significantly improved handoff success rates are illustrated via experiments using floor plans of various scales.
Size preserving tracking automatically adjusts the camera’s zoom for a consistent view of the object of interest. Target scale estimation is carried out based on the paraperspective projection model which compensates for the center offset and considers system latency and tracking errors. A computationally efficient foreground segmentation strategy, 3D affine shapes, is proposed. The 3D affine shapes feature direct and real-time implementation and improved flexibility in accommodating the target’s 3D motion, including off-plane rotations. The effectiveness of the scale estimation and foreground segmentation algorithms is validated via both offline and real-time tracking of pedestrians at various resolution levels.
Face image quality assessment and enhancement compensate for the performance degradations in face recognition rates caused by high system magnifications and long observation distances. A class of adaptive sharpness measures is proposed to evaluate and predict this degradation. A wavelet based enhancement algorithm with automated frame selection is developed and proves efficient by a considerably elevated face recognition rate for severely blurred long range face images
Object Tracking and Mensuration in Surveillance Videos
This thesis focuses on tracking and mensuration in surveillance videos. The
first part of the thesis discusses several object tracking approaches based on the
different properties of tracking targets. For airborne videos, where the targets are
usually small and with low resolutions, an approach of building motion models for
foreground/background proposed in which the foreground target is simplified as a
rigid object. For relatively high resolution targets, the non-rigid models are applied.
An active contour-based algorithm has been introduced. The algorithm is based on
decomposing the tracking into three parts: estimate the affine transform parameters
between successive frames using particle filters; detect the contour deformation using
a probabilistic deformation map, and regulate the deformation by projecting the
updated model onto a trained shape subspace. The active appearance Markov chain
(AAMC). It integrates a statistical model of shape, appearance and motion. In the
AAMC model, a Markov chain represents the switching of motion phases (poses),
and several pairwise active appearance model (P-AAM) components characterize the
shape, appearance and motion information for different motion phases. The second
part of the thesis covers video mensuration, in which we have proposed a heightmeasuring
algorithm with less human supervision, more flexibility and improved
robustness. From videos acquired by an uncalibrated stationary camera, we first
recover the vanishing line and the vertical point of the scene. We then apply a single
view mensuration algorithm to each of the frames to obtain height measurements.
Finally, using the LMedS as the cost function and the Robbins-Monro stochastic
approximation (RMSA) technique to obtain the optimal estimate