HLD: A robust descriptor for line matching

Line matching plays an important role in many applications, such as image registration, 3D reconstruction, object recognition and video understanding. However, compared with other features (such as point, region) matching, it has made little progress in recent years. In this paper, we investigate the problem of matching line segments automatically only from their neighborhood appearance, without any constraints or priori knowledge. A novel line descriptor called HLD descriptor is proposed for this purpose, which is constructed by the following three steps: (1) Line support region (LSR) is defined, then divided into a series of overlapped sub-regions with the same size; (2) Line description matrix (DM) is formed by characterizing each sub-region into a vector; (3) HLD descriptor is built by computing mean and standard deviation of DM column vectors. Experimental results show that HLD descriptor is highly distinctive and very robust for line matching on real images.