Zero-Shot Learning Based on Multitask Extended Attribute Groups

Abstract

Since the learning of attribute classifiers is independent of the learning of object classifier in zero-shot learning, it is difficult to guarantee that the learned attribute classifiers are optimal for the subsequent object recognition tasks. Therefore, a novel zero-shot learning method based on multitask extended attribute groups (MTEAGs) is proposed by using the multitask learning framework and grouping idea. First, we used an unsupervised clustering method to group the attributes and object classes of training images. Then, based on the obtained attribute and class groups, we constructed the group-based attribute/object classifier collaborative learning model where the class groups are viewed as the extension of attribute groups. In order to explore the shared features within a group as well restrict the feature sharing between groups, we applied the structured sparse method to constrain the model parameter matrix. At last, a hybrid zero-shot classifying model is designed by simultaneously considering the class–class and class–attribute matrices to predict the class labels of testing images, where the class–class relationship is measured by the Jaccard similarity coefficient. Experiments on two popular attribute datasets show that, MTEAG can yield higher zero-shot image classification accuracy compared with several baselines.