The most performant spatio-temporal action localisation models use external person proposals and complex external memory banks. We propose a fully end-to-end, purely-transformer based model that directly ingests an input video, and outputs tubelets -- a sequence of bounding boxes and the action classes at each frame. Our flexible model can be trained with either sparse bounding-box supervision on individual frames, or full tubelet annotations. And in both cases, it predicts coherent tubelets as the output. Moreover, our end-to-end model requires no additional pre-processing in the form of proposals, or post-processing in terms of non-maximal suppression. We perform extensive ablation experiments, and significantly advance the state-of-the-art results on four different spatio-temporal action localisation benchmarks with both sparse keyframes and full tubelet annotations.
@article{arxiv.2304.12160,
title = {End-to-End Spatio-Temporal Action Localisation with Video Transformers},
author = {Alexey Gritsenko and Xuehan Xiong and Josip Djolonga and Mostafa Dehghani and Chen Sun and Mario Lučić and Cordelia Schmid and Anurag Arnab},
journal= {arXiv preprint arXiv:2304.12160},
year = {2023}
}