We introduce a novel unsupervised domain adaptation approach for object detection. We aim to alleviate the imperfect translation problem of pixel-level adaptations, and the source-biased discriminativity problem of feature-level adaptations simultaneously. Our approach is composed of two stages, i.e., Domain Diversification (DD) and Multi-domain-invariant Representation Learning (MRL). At the DD stage, we diversify the distribution of the labeled data by generating various distinctive shifted domains from the source domain. At the MRL stage, we apply adversarial learning with a multi-domain discriminator to encourage feature to be indistinguishable among the domains. DD addresses the source-biased discriminativity, while MRL mitigates the imperfect image translation. We construct a structured domain adaptation framework for our learning paradigm and introduce a practical way of DD for implementation. Our method outperforms the state-of-the-art methods by a large margin of 3%~11% in terms of mean average precision (mAP) on various datasets.

该研究介绍了一种针对目标检测的新型无监督域适应方法，通过域多样性和多域不变表示学习两个阶段来缓解像素级适应不完美和特征级适应带来的源偏差歧视。该方法在各种数据集上mAP平均精度方面的表现优于现有技术达到了3%~11%的大幅度提升。

多样化匹配：一种面向领域适应的目标检测表示学习范式