  In this paper, we introduce a novel network, called discriminative feature
network (DFNet), to address the unsupervised video object segmentation task. To
capture the inherent correlation among video frames, we learn discriminative
features (D-features) from the input images that reveal feature distribution
from a global perspective. The D-features are then used to establish
correspondence with all features of test image under conditional random field
(CRF) formulation, which is leveraged to enforce consistency between pixels.
The experiments verify that DFNet outperforms state-of-the-art methods by a
large margin with a mean IoU score of 83.4% and ranks first on the DAVIS-2016
leaderboard while using much fewer parameters and achieving much more efficient
performance in the inference phase. We further evaluate DFNet on the FBMS
dataset and the video saliency dataset ViSal, reaching a new state-of-the-art.
To further demonstrate the generalizability of our framework, DFNet is also
applied to the image object co-segmentation task. We perform experiments on a
challenging dataset PASCAL-VOC and observe the superiority of DFNet. The
thorough experiments verify that DFNet is able to capture and mine the
underlying relations of images and discover the common foreground objects.
