I. Introduction
Image semantic segmentation is one of the most basic techniques in computer vision. It is to assign a semantic label to each pixel in the image and divides adjacent pixels with the same semantic label into the same region. Each region is independent and has the same attributions belonging to the same object class, such as color, shape, quality, and illumination. Semantic segmentation is the most basic and critical technology in object recognition, video data monitoring, and other subsequent processing. It plays an important role in road and building measurement, urban planning, and road monitoring. However, image semantic segmentation is still a very challenging task in road detection. There are some common problems in semantic segmentation [1], [2], such as the mismatch of object relations, the misjudgment of confusing object categories, and the neglect of nonobvious categories, which are affected by global background information partially. These problems make the classification of image pixels more difficult, which causes the prediction result to deviate from the ground truth.