Article

Alternative approach for automatic evaluation of traffic sign visibility

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Abstract

In the present paper we propose an automated low cost method for evaluating the visibility of traffic signs. Since the traffic signs may present difficulties to be seen at night and whose main propose is to advice the motorists, we decided to do the measurement at night, within a car and using the headlamps as illumination sources. In this way we evaluate the surface reflectivity of the sign and the influence of bad orientation or positioning of the sign relative to the vehicle headlamps or road. The visibility parameter of a traffic sign is then calculated from a sequence of images of the sign captured with a colour digital camera at different distances sign-vehicle. The key point for an automated process is to detect and recognise automatically the sign from the captured images. This is done by a software which uses Support Vector Machines (SVM) as a novel classification technique. As example, this technique has been applied successfully over three different signs with three different degrees of surface deterioration. The influence of relative orientation vehicle-sign is also analyzed by a sign placed on a curved road.

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CCD matrix detector for photometry
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