  In this paper, we propose a novel iterative multi-task framework to complete
the segmentation mask of an occluded vehicle and recover the appearance of its
invisible parts. In particular, to improve the quality of the segmentation
completion, we present two coupled discriminators and introduce an auxiliary 3D
model pool for sampling authentic silhouettes as adversarial samples. In
addition, we propose a two-path structure with a shared network to enhance the
appearance recovery capability. By iteratively performing the segmentation
completion and the appearance recovery, the results will be progressively
refined. To evaluate our method, we present a dataset, the Occluded Vehicle
dataset, containing synthetic and real-world occluded vehicle images. We
conduct comparison experiments on this dataset and demonstrate that our model
outperforms the state-of-the-art in tasks of recovering segmentation mask and
appearance for occluded vehicles. Moreover, we also demonstrate that our
appearance recovery approach can benefit the occluded vehicle tracking in
real-world videos.
