Existing techniques to adapt semantic segmentation networks across the source
and target domains within deep convolutional neural networks (CNNs) deal with
all the samples from the two domains in a global or category-aware manner. They
do not consider an inter-class variation within the target domain itself or
estimated category, providing the limitation to encode the domains having a
multi-modal data distribution. To overcome this limitation, we introduce a
learnable clustering module, and a novel domain adaptation framework called
cross-domain grouping and alignment. To cluster the samples across domains with
an aim to maximize the domain alignment without forgetting precise segmentation
ability on the source domain, we present two loss functions, in particular, for
encouraging semantic consistency and orthogonality among the clusters. We also
present a loss so as to solve a class imbalance problem, which is the other
limitation of the previous methods. Our experiments show that our method
consistently boosts the adaptation performance in semantic segmentation,
outperforming the state-of-the-arts on various domain adaptation settings.

本文提出一种可学习的聚类模块以及称为跨域分组和对齐的新颖域自适应框架，以解决先前方法的限制，包括多模态数据分布和类别不平衡问题。我们声称通过鼓励对聚类之间的语义一致性和正交性进行两个损失函数，解决了聚类中的域对齐问题，而且还提出一种解决类不平衡的问题的损失函数。实验证明，我们的方法在各种域适应设置中均能提高语义分割的适应性能，并超越了现有技术水平。