Domain adaptation for visual recognition has undergone great progress in the
past few years. Nevertheless, most existing methods work in the so-called
closed-set scenario, assuming that the classes depicted by the target images
are exactly the same as those of the source domain. In this paper, we tackle
the more challenging, yet more realistic case of open-set domain adaptation,
where new, unknown classes can be present in the target data. While, in the
unsupervised scenario, one cannot expect to be able to identify each specific
new class, we aim to automatically detect which samples belong to these new
classes and discard them from the recognition process. To this end, we rely on
the intuition that the source and target samples depicting the known classes
can be generated by a shared subspace, whereas the target samples from unknown
classes come from a different, private subspace. We therefore introduce a
framework that factorizes the data into shared and private parts, while
encouraging the shared representation to be discriminative. Our experiments on
standard benchmarks evidence that our approach significantly outperforms the
state-of-the-art in open-set domain adaptation.

我们提出了一个能够将数据因子化为共享和私有部分并鼓励共享表示具有判别性的框架，以自动检测目标数据中出现的新类别并将其丢弃，从而在开放域适应中显著优于现有技术。