Robust Lane Marking Detection Algorithm Using Drivable Area Segmentation and Extended SLT In this paper, a robust lane detection algorithm is proposed, where the vertical road profile of the road is estimated using dynamic programming from the vdisparity map and, based on the estimated profile, the road area is segmented. Since the lane markings are on the road area and any feature point above the ground will be a noise source for the lane detection, a mask is created for the road area to remove some of the noise for lane detection. The estimated mask is multiplied by the lane feature map in a birdxe2x80x99s eye view (BEV). The lane feature points are extracted by using an extended version of symmetrical local threshold (SLT), which not only considers dark light dark transition (DLD) of the lane markings, like (SLT), but also considers parallelism on the lane marking borders. The segmentation then uses only the feature points that are on the road area. A maximum of two linear lane markings are detected using an efficient 1D Hough transform. Then, the detected linear lane markings are used to create a region of interest (ROI) for parabolic lane detection. Finally, based on the estimated region of interest, parabolic lane models are fitted using robust fitting. Due to the robust lane feature extraction and road area segmentation, the proposed algorithm robustly detects lane markings and achieves lane marking detection with an accuracy of 91% when tested on a sequence from the KITTI dataset.

Lane Marking Learning based on Crowdsourced Data In this paper, we propose a new algorithm that derives lane marking maps from crowdsourced data. We process the data in four steps: (i) We make use of a point landmark map and, if available, an existent lane marking map for trajectory optimization and alignment, (ii) use a custom DBSCAN variant to cluster observations that belong to the same lane marking, (iii) apply a novel graph fitting approach to extract lane marking dashes, lines and even complex structures such as splits and merges and (iv) optimize the graph geometry with domain knowledge. The process of pointlandmark and lane markingbased trajectory alignment and the lane marking derivation is repeated iteratively to improve the results. Evaluation is carried out on a 9km highway section by comparison with high accuracy aerial photographs and manually labeled ground truth lane markings.