Transductive transfer machine

Abstract

We propose a pipeline for transductive transfer learning and demonstrate it in computer vision tasks. In pattern classification, methods for transductive transfer learning (also known as unsupervised domain adaptation) are designed to cope with cases in which one cannot assume that training and test sets are sampled from the same distribution, i.e., they are from different domains. However, some unlabelled samples that belong to the same domain as the test set (i.e. the target domain) are available, enabling the learner to adapt its parameters. We approach this problem by combining three methods that transform the feature space. The first finds a lower dimensional space that is shared between source and target domains. The second uses local transformations applied to each source sample to further increase the similarity between the marginal distributions of the datasets. The third applies one transformation per class label, aiming to increase the similarity between the posterior probability of samples in the source and target sets. We show that this combination leads to an improvement over the state-of-the-art in crossdomain image classification datasets, using raw images or basic features and a simple one-nearest-neighbour classifier.