4,603 research outputs found
leave a trace - A People Tracking System Meets Anomaly Detection
Video surveillance always had a negative connotation, among others because of
the loss of privacy and because it may not automatically increase public
safety. If it was able to detect atypical (i.e. dangerous) situations in real
time, autonomously and anonymously, this could change. A prerequisite for this
is a reliable automatic detection of possibly dangerous situations from video
data. This is done classically by object extraction and tracking. From the
derived trajectories, we then want to determine dangerous situations by
detecting atypical trajectories. However, due to ethical considerations it is
better to develop such a system on data without people being threatened or even
harmed, plus with having them know that there is such a tracking system
installed. Another important point is that these situations do not occur very
often in real, public CCTV areas and may be captured properly even less. In the
artistic project leave a trace the tracked objects, people in an atrium of a
institutional building, become actor and thus part of the installation.
Visualisation in real-time allows interaction by these actors, which in turn
creates many atypical interaction situations on which we can develop our
situation detection. The data set has evolved over three years and hence, is
huge. In this article we describe the tracking system and several approaches
for the detection of atypical trajectories
Are tiled display walls needed for astronomy?
Clustering commodity displays into a Tiled Display Wall (TDW) provides a
cost-effective way to create an extremely high resolution display, capable of
approaching the image sizes now gen- erated by modern astronomical instruments.
Astronomers face the challenge of inspecting single large images, many similar
images simultaneously, and heterogeneous but related content. Many research
institutions have constructed TDWs on the basis that they will improve the
scientific outcomes of astronomical imagery. We test this concept by presenting
sample images to astronomers and non- astronomers using a standard desktop
display (SDD) and a TDW. These samples include standard English words, wide
field galaxy surveys and nebulae mosaics from the Hubble telescope. These
experiments show that TDWs provide a better environment for searching for small
targets in large images than SDDs. It also shows that astronomers tend to be
better at searching images for targets than non-astronomers, both groups are
generally better when employing physical navigation as opposed to virtual
navigation, and that the combination of two non-astronomers using a TDW rivals
the experience of a single astronomer. However, there is also a large
distribution in aptitude amongst the participants and the nature of the content
also plays a significant role is success.Comment: 19 pages, 15 figures, accepted for publication in PASA (Publications
of the Astronomical Society of Australia
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