11,661 research outputs found
Strategies for Searching Video Content with Text Queries or Video Examples
The large number of user-generated videos uploaded on to the Internet
everyday has led to many commercial video search engines, which mainly rely on
text metadata for search. However, metadata is often lacking for user-generated
videos, thus these videos are unsearchable by current search engines.
Therefore, content-based video retrieval (CBVR) tackles this metadata-scarcity
problem by directly analyzing the visual and audio streams of each video. CBVR
encompasses multiple research topics, including low-level feature design,
feature fusion, semantic detector training and video search/reranking. We
present novel strategies in these topics to enhance CBVR in both accuracy and
speed under different query inputs, including pure textual queries and query by
video examples. Our proposed strategies have been incorporated into our
submission for the TRECVID 2014 Multimedia Event Detection evaluation, where
our system outperformed other submissions in both text queries and video
example queries, thus demonstrating the effectiveness of our proposed
approaches
A distributed camera system for multi-resolution surveillance
We describe an architecture for a multi-camera, multi-resolution surveillance system. The aim is to support a set of distributed static and pan-tilt-zoom (PTZ) cameras and visual tracking algorithms, together with a central supervisor unit. Each camera (and possibly pan-tilt device) has a dedicated process and processor.
Asynchronous interprocess communications and archiving of data are achieved in a simple and effective way via a central repository, implemented using an SQL database.
Visual tracking data from static views are stored dynamically into tables in the database via client calls to the SQL server. A supervisor process running on the SQL server determines if active zoom cameras should be dispatched to observe a particular target, and this message is effected via writing demands into another database table.
We show results from a real implementation of the system comprising one static camera overviewing the environment under consideration and a PTZ camera operating
under closed-loop velocity control, which uses a fast and robust level-set-based region tracker. Experiments demonstrate the effectiveness of our approach and its feasibility to multi-camera systems for intelligent surveillance
RoboTSP - A Fast Solution to the Robotic Task Sequencing Problem
In many industrial robotics applications, such as spot-welding,
spray-painting or drilling, the robot is required to visit successively
multiple targets. The robot travel time among the targets is a significant
component of the overall execution time. This travel time is in turn greatly
affected by the order of visit of the targets, and by the robot configurations
used to reach each target. Therefore, it is crucial to optimize these two
elements, a problem known in the literature as the Robotic Task Sequencing
Problem (RTSP). Our contribution in this paper is two-fold. First, we propose a
fast, near-optimal, algorithm to solve RTSP. The key to our approach is to
exploit the classical distinction between task space and configuration space,
which, surprisingly, has been so far overlooked in the RTSP literature. Second,
we provide an open-source implementation of the above algorithm, which has been
carefully benchmarked to yield an efficient, ready-to-use, software solution.
We discuss the relationship between RTSP and other Traveling Salesman Problem
(TSP) variants, such as the Generalized Traveling Salesman Problem (GTSP), and
show experimentally that our method finds motion sequences of the same quality
but using several orders of magnitude less computation time than existing
approaches.Comment: 6 pages, 7 figures, 1 tabl
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