Collecting well-annotated image datasets to train modern machine learning algorithms is prohibitively expensive for many tasks. One appealing alternative is rendering synthetic data where ground-truth annotations are generated automatically. Unfortunately, models trained purely on rendered images often fail to generalize to real images. To address this shortcoming, prior work introduced unsupervised domain adaptation algorithms that attempt to map representations between the two domains or learn to extract features that are domain-invariant. In this work, we present a new approach that learns, in an unsupervised manner, a transformation in the pixel space from one domain to the other. Our generative adversarial network (GAN)-based method adapts source-domain images to appear as if drawn from the target domain. Our approach not only produces plausible samples, but also outperforms the state-of-the-art on a number of unsupervised domain adaptation scenarios by large margins. Finally, we demonstrate that the adaptation process generalizes to object classes unseen during training.

本文提出了一种基于生成对抗网络的方法，通过在像素空间中学习一种转换方法，将源域图像适应为与目标域相同的样子，以解决渲染图像训练模型泛化性不强的问题。该方法不仅可以生成逼真的样本，而且在许多无监督域适应场景中均优于现有技术，并证明了适应过程对于训练期间未被观察到的物体类别的泛化性。

无监督像素级域自适应生成对抗网络