  Road extraction from very high resolution satellite (VHR) images is one of
the most important topics in the field of remote sensing. In this paper, we
propose an efficient Non-Local LinkNet with non-local blocks that can grasp
relations between global features. This enables each spatial feature point to
refer to all other contextual information and results in more accurate road
segmentation. In detail, our single model without any post-processing like CRF
refinement, performed better than any other published state-of-the-art ensemble
model in the official DeepGlobe Challenge. Moreover, our NL-LinkNet beat the
D-LinkNet, the winner of the DeepGlobe challenge, with 43 \% less parameters,
less giga floating-point operations per seconds (GFLOPs) and shorter training
convergence time. We also present empirical analyses on the proper usages of
non-local blocks for the baseline model.
