  In this paper we present a machine vision system to efficiently monitor,
analyze and present visual data acquired with a railway overhead gantry
equipped with multiple cameras. This solution aims to improve the safety of
daily life railway transportation in a two- fold manner: (1) by providing
automatic algorithms that can process large imagery of trains (2) by helping
train operators to keep attention on any possible malfunction. The system is
designed with the latest cutting edge, high-rate visible and thermal cameras
that ob- serve a train passing under an railway overhead gantry. The machine
vision system is composed of three principal modules: (1) an automatic wagon
identification system, recognizing the wagon ID according to the UIC
classification of railway coaches; (2) a temperature monitoring system; (3) a
system for the detection, localization and visualization of the pantograph of
the train. These three machine vision modules process batch trains sequences
and their resulting analysis are presented to an operator using a multitouch
user interface. We detail all technical aspects of our multi-camera portal: the
hardware requirements, the software developed to deal with the high-frame rate
cameras and ensure reliable acquisition, the algorithms proposed to solve each
computer vision task, and the multitouch interaction and visualization
interface. We evaluate each component of our system on a dataset recorded in an
ad-hoc railway test-bed, showing the potential of our proposed portal for train
safety assessment.
