Automatic 3d Extraction of Rectangular Roadmarks with Centimeter Accuracy from Stereo-pairs of a Ground-based Mobile Mapping System

The present paper is an extension of a previous work presented in (Soheilian et al., 2006a) in which an automatic algorithm of zebracrossing reconstruction from stereo-pairs of a mobile mapping system was proposed. The method has been adapted to reconstruct different types of rectangular roadmarks. The algorithm can be summarized in three main points. First of all a 3D edge point reconstruction is performed by a dynamic programming optimization matching conjugate epipolar lines. Then during a detection step, a dashed-line signature is recognized and sets of candidate line-segments are provided. A final modelling step rebuilds optimally each strip of the detected dashed-line. The method is evaluated on a set of 150 stereo-pairs. It provides promising results with a detection rate which is higher than 86%. Geometric accuracy of the method is about 2 cm for all of the reconstructed zebra-crossing and dashed-lines strips.