Discriminative feature learning for multimodal classification

The purpose of this thesis is to tackle two related topics: multimodal classification and objective functions to improve the discriminative power of features. First, I worked on image and text classification tasks and performed many experiments to show the effectiveness of different approaches available in literature. Then, I introduced a novel methodology which can classify multimodal documents using singlemodal classifiers merging textual and visual information into images and a novel loss function to improve separability between samples of a dataset. Results show that exploiting multimodal data increases performances on classification tasks rather than using traditional single-modality methods. Moreover the introduced GIT loss function is able to enhance the discriminative power of features, lowering intra-class distance and raising inter-class distance between samples of a multiclass dataset.