Classify social image by integrating multi-modal content.

There is a growing volume of social images with the development of social networks and digital cameras. Usually, these images are annotated with textual tags besides the visual content. It is quite urgent to automatically organize and manage this large number of social images. Image classification is the basic task of these applications and has attracted great research efforts. Though there are many researches on image classification, it is of considerable challenge to integrate the multi-modal content of social images simultaneously for classification, since the textual content and visual content are represented in two heterogeneous feature spaces. In this paper, we proposed a multi-modal learning method to integrate multi-modal features through their correlation seamlessly. Specifically, we learn two linear classification modules for the two types of features, and then they are integrated by the <italic>l</italic>₂ normalization method via a joint model. Each classier is normalized with <italic>l</italic>_2,1 to reduce the effect of the noisy features by selecting a subset of more important features. With the joint model, the classification based on visual features can be reinforced by the classification based on textual features, and vice verse. Then, the test image is classified based on both the textual features and visual features by combing the results of the two classifiers. Experiments conducted on real-world social image datasets demonstrate the superiority of our proposed method compared with the representative baselines. [ABSTRACT FROM AUTHOR]