task_categories:image-classification task_categories:object-detection task_categories:other task_ids:multi-class-image-classification annotations_creators:crowdsourced language_creators:expert-generated multilinguality:monolingual source_datasets:original language:en license:cc-by-nc-4.0 size_categories:1K<n<10K format:webdataset modality:text modality:video library:datasets library:webdataset library:mlcroissant arxiv:2105.07404 region:us video action detection spatial-temporal action localization