Reverse and boundary attention network for road segmentation

Road segmentation is an essential task to perceive the driving environment in autonomous driving and advanced driver assistance systems. With the development of deep learning, road segmentation has achieved great progress in recent years. However, there still remain some problems including the inaccurate road boundary and the illumination variations such as shadows and over-exposure regions. To solve these problems, we propose a residual learning-based network architecture with residual refinement module composed of the reverse attention and boundary attention units for road segmentation. The network first predicts a coarse road region from deeper-level feature maps and gradually refines the prediction by learning the residual in a top-down approach. The reverse and boundary attention units in residual refinement module guide the network to focus on the features in the previously missing region and the region near the road boundary. In addition, we introduce the boundary-aware weighted loss to reduce the false prediction. Experimental results demonstrate that the proposed approach outperforms the state-of-the-art methods in terms of the segmentation accuracy in various benchmark datasets for traffic scene understanding.