Cross-modal Manifold Cutmix for Self-supervised Video Representation Learning

In this paper, we address the challenge of obtaining large-scale unlabelled video datasets for contrastive representation learning in real-world applications. We present a novel video augmentation technique for self-supervised learning, called Cross-Modal Manifold Cutmix (CMMC), which generates augmented samples by combining different modalities in videos. By embedding a video tesseract into another across two modalities in the feature space, our method enhances the quality of learned video representations. We perform extensive experiments on two small-scale video datasets, UCF101 and HMDB51, for action recognition and video retrieval tasks. Our approach is also shown to be effective on the NTU dataset with limited domain knowledge. Our CMMC achieves comparable performance to other self-supervised methods while using less training data for both downstream tasks.