LAUSR

Adversarial domain adaptation has been an effective approach for learning domain-invariant features by adversarial training. In this paper, we propose a novel adversarial domain adaptation approach defined in the spherical feature space, in which we define spherical classifier for label prediction and spherical domain discriminator for discriminating domain labels. In the spherical feature space, we develop a robust pseudo-label loss to utilize pseudo-labels robustly, which weights the importance of the estimated labels of target data by the posterior probability of correct labeling, modeled by the Gaussian-uniform mixture model in the spherical space. Our proposed approach can be generally applied to both unsupervised and semi-supervised domain adaptation settings. In particular, to tackle the semi-supervised domain adaptation setting where a few labeled target data are available for training, we proposed a novel reweighted adversarial training strategy for effectively reducing the intra-domain discrepancy within the target domain. We also present theoretical analysis for the proposed method based on the domain adaptation theory. Extensive experiments are conducted on benchmarks for multiple applications, including object recognition, digit recognition, and face recognition. The results show that our method either surpasses or is competitive compared with recent methods for both unsupervised and semi-supervised domain adaptation.