Bat: Bi-Alignment Based On Transformation in Multi-Target Domain Adaptation for Semantic Segmentation

While enlightening progress has been made recently in single-target domain adaptive semantic segmentation (ST-DASS), the multi-peak distributed multi-target domain cannot be directly aligned well with the single-peak distributed source domain. As a result, it is impossible for existing methods to handle the more realistic multi-target domain adaptive semantic segmentation (MT-DASS) tasks. To solve this problem, we propose a Bi-Alignment framework based on Transformation (BAT). Specifically, we employ the Fourier style transform to convert the style of the source domain to that of the target domain without training any style transfer networks. In this way, we transform the single-peak distributed source domain into a multi-peak distribution that resembles the multi-target domain. Then, we perform fine-grained global and local dual distribution alignment between the same style of source-target domain pairs to achieve a multi-to-multi distribution alignment. Finally, self-training is utilized to further improve the network’s discriminability. Experimental results show that our approach achieves competitive results over state-of-the-art methods.