  Scene Graph Generation (SGG) aims to detect all the visual relation triplets
<sub, pred, obj> in a given image. With the emergence of various advanced
techniques for better utilizing both the intrinsic and extrinsic information in
each relation triplet, SGG has achieved great progress over the recent years.
However, due to the ubiquitous long-tailed predicate distributions, today's SGG
models are still easily biased to the head predicates. Currently, the most
prevalent debiasing solutions for SGG are re-balancing methods, e.g., changing
the distributions of original training samples. In this paper, we argue that
all existing re-balancing strategies fail to increase the diversity of the
relation triplet features of each predicate, which is critical for robust SGG.
To this end, we propose a novel Compositional Feature Augmentation (CFA)
strategy, which is the first unbiased SGG work to mitigate the bias issue from
the perspective of increasing the diversity of triplet features. Specifically,
we first decompose each relation triplet feature into two components: intrinsic
feature and extrinsic feature, which correspond to the intrinsic
characteristics and extrinsic contexts of a relation triplet, respectively.
Then, we design two different feature augmentation modules to enrich the
feature diversity of original relation triplets by replacing or mixing up
either their intrinsic or extrinsic features from other samples. Due to its
model-agnostic nature, CFA can be seamlessly incorporated into various SGG
frameworks. Extensive ablations have shown that CFA achieves a new
state-of-the-art performance on the trade-off between different metrics.
