eyeTrain Brochure - Petards Group plc

On Board Surveillance
Key Components
Facts:
Wide Dynamic Range Pixel-Level Exposure Control
Case Study: ScotRail
When First ScotRail was looking at on-board surveillance
options, they turned to Petards to provide the most
sophisticated, reliable and comprehensive security camera
system available.
Up to five state-of-the-art CCTV cameras were installed in
each carriage, capable of recording high-resolution images
from every angle. A total of 2,000 cameras saw almost every
First ScotRail train covered within two years.
Today, the multi-million-pound system remains one of
the most hi-tech on the rail network, with over 230 trains
equipped.
First ScotRail’s entire diesel fleet and almost all its electric
trains were covered in the project.
Petards can offer a camera with an advanced exposure
control system, which handles the light in the scene in
much the same way as the human eye. This means that
there are fewer areas where the image is either under- or
over-exposed.
The above comparative images show the exposure
improvements with PIXIM image sensors. Contrast
problems with traditional cameras are experienced where
the items of interest are illuminated with greatly different
amounts of light.
The images on the left are from an eyeTrain pixel-level
exposure camera, it can be seen that there is good contrast
in all areas such that you can view detail in both the bright
and dark areas.
Andy Mellors, Engineering Director at First Group said: “It is
essential the travelling public can feel confident and secure.
We were impressed with the high-quality images from the
new digital technology.”
Following on from this project, Petards again worked
successfully with First Group.
This time on the Great Western line, where eyeTrain Onboard
was fitted to the full fleet of DMU’s.
Feedback from this second project has again been glowing
with British Transport Police delighted with the evidence
the system has provided, particularly due to the clarity of
image that eyeTrain provides.
The combination of internal and external light sources
and the rapidly changing position of a vehicle provide an
environment of adverse lighting conditions.
While the human eye can rapidly adjust to widely differing
light levels, normal video cameras cannot cope with large
light differences simply because they have a limited range
of contrast.
In order to expose the inside of the vehicle in the images
above, a conventional camera (images on the right)
overexposed the outside view, the consequence is that the
outside view has ‘saturated’ highlights – there is no detail in
the very bright areas. If the same camera had exposed the
outside view correctly, the inside of the vehicle would have
been rendered very dark; this time there would have been
no detail in the very dark areas.