Planar projection stereopsis method for road extraction

This paper presents a new road extraction method for an autonomous vehicle which can acquire a road area by using height information of objects. Since a road area can be assumed to be a sequence of a flat plane in front of a vehicle, the road's height information is very effective for extracting a road area. For the purpose, the authors propose a new approach named the planar projection stereopsis (PPS) method which can easily decide whether each point in stereo images exists on the road plane or not. At first, PPS calculates a planar equation representing a road area by using height and pose of a camera in the vehicle. Next, stereo images are projected to the plane, where corresponding points are projected to the same positions on a certain road area if they really exist on a road plane, while corresponding points with different heights from the road plane are projected to different positions in each stereo image. Planar projection description is obtained by a subtraction between projected images from a set of stereo images and a road area can be represented by a set of points with small values. Experimental results for real road scenes have shown the effectiveness of the proposed method.