  In this paper, we tackle the problem of learning visual representations from
unlabeled scene-centric data. Existing works have demonstrated the potential of
utilizing the underlying complex structure within scene-centric data; still,
they commonly rely on hand-crafted objectness priors or specialized pretext
tasks to build a learning framework, which may harm generalizability. Instead,
we propose contrastive learning from data-driven semantic slots, namely
SlotCon, for joint semantic grouping and representation learning. The semantic
grouping is performed by assigning pixels to a set of learnable prototypes,
which can adapt to each sample by attentive pooling over the feature and form
new slots. Based on the learned data-dependent slots, a contrastive objective
is employed for representation learning, which enhances the discriminability of
features, and conversely facilitates grouping semantically coherent pixels
together. Compared with previous efforts, by simultaneously optimizing the two
coupled objectives of semantic grouping and contrastive learning, our approach
bypasses the disadvantages of hand-crafted priors and is able to learn
object/group-level representations from scene-centric images. Experiments show
our approach effectively decomposes complex scenes into semantic groups for
feature learning and significantly benefits downstream tasks, including object
detection, instance segmentation, and semantic segmentation. Code is available
at: https://github.com/CVMI-Lab/SlotCon.
