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Patterns Of Motion: Discovery And Generalized Representation, Imran Saleemi
Patterns Of Motion: Discovery And Generalized Representation, Imran Saleemi
Electronic Theses and Dissertations
In this dissertation, we address the problem of discovery and representation of motion patterns in a variety of scenarios, commonly encountered in vision applications. The overarching goal is to devise a generic representation, that captures any kind of object motion observable in video sequences. Such motion is a significant source of information typically employed for diverse applications such as tracking, anomaly detection, and action and event recognition. We present statistical frameworks for representation of motion characteristics of objects, learned from tracks or optical flow, for static as well as moving cameras, and propose algorithms for their application to a variety …
Feature Pruning For Action Recognition In Complex Environment, Adarsh Nagaraja
Feature Pruning For Action Recognition In Complex Environment, Adarsh Nagaraja
Electronic Theses and Dissertations
A significant number of action recognition research efforts use spatio-temporal interest point detectors for feature extraction. Although the extracted features provide useful information for recognizing actions, a significant number of them contain irrelevant motion and background clutter. In many cases, the extracted features are included as is in the classification pipeline, and sophisticated noise removal techniques are subsequently used to alleviate their effect on classification. We introduce a new action database, created from the Weizmann database, that reveals a significant weakness in systems based on popular cuboid descriptors. Experiments show that introducing complex backgrounds, stationary or dynamic, into the video …
Towards Calibration Of Optical Flow Of Crowd Videos Using Observed Trajectories, Iman K. Elbadramany
Towards Calibration Of Optical Flow Of Crowd Videos Using Observed Trajectories, Iman K. Elbadramany
Electronic Theses and Dissertations
The need exists for finding a quantitative method for validating crowd simulations. One approach is to use optical flow of videos of real crowds to obtain velocities that can be used for comparison to simulations. Optical flow, in turn, needs to be calibrated to be useful. It is essential to show that optical flow velocities obtained from crowd videos can be mapped into the spatially averaged velocities of the observed trajectories of crowd members, and to quantify the extent of the correlation of the results. This research investigates methods to uncover the best conditions for a good correlation between optical …