arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2109.11265cs.CV
收藏

通过并行回归实现端到端密集视频定位

End-to-End Dense Video Grounding via Parallel Regression

Nanjing University(南京大学);Alibaba Group(阿里巴巴集团)

Fengyuan Shi, Weilin Huang, Limin Wang

AI总结:

本文提出 PRVG 框架,将密集视频定位建模为语言条件并行回归,以语言为查询直接预测多个时刻边界,并在 ActivityNet Captions 和 TACoS 上取得显著优势。

摘要:

视频定位旨在给定语言查询时,在未裁剪视频中定位相应的视频时刻。现有方法通常以间接方式处理该任务,将其转化为提议-匹配或融合-检测问题。求解这些替代问题往往需要在训练期间进行复杂的标签分配,并手工去除近似重复的结果。同时,现有工作通常聚焦于以单句作为输入的稀疏视频定位,由于描述不清晰,可能导致定位存在歧义。本文处理一个新的密集视频定位问题,即以段落为输入同时定位多个时刻。从将视频定位视为语言条件回归的视角出发,我们通过重新利用类似 Transformer 的架构(PRVG),提出一种端到端并行解码范式。PRVG 的关键设计是使用语言作为查询,并基于语言调制的视觉表示直接回归时刻边界。得益于设计简洁性,PRVG 框架可应用于不同测试方案(稀疏或密集定位),并支持无需任何后处理技术的高效推理。此外,我们设计了鲁棒的提议级注意力损失来指导 PRVG 训练,该损失对时刻时长保持不变,并有助于模型收敛。我们在 ActivityNet Captions 和 TACoS 两个视频定位基准上进行实验,结果表明 PRVG 显著优于以往方法。我们还开展深入研究,考察并行回归范式在视频定位上的有效性。

英文摘要:

Video grounding aims to localize the corresponding video moment in an untrimmed video given a language query. Existing methods often address this task in an indirect way, by casting it as a proposal-and-match or fusion-and-detection problem. Solving these surrogate problems often requires sophisticated label assignment during training and hand-crafted removal of near-duplicate results. Meanwhile, existing works typically focus on sparse video grounding with a single sentence as input, which could result in ambiguous localization due to its unclear description. In this paper, we tackle a new problem of dense video grounding, by simultaneously localizing multiple moments with a paragraph as input. From a perspective on video grounding as language conditioned regression, we present an end-to-end parallel decoding paradigm by re-purposing a Transformer-alike architecture (PRVG). The key design in our PRVG is to use languages as queries, and directly regress the moment boundaries based on language-modulated visual representations. Thanks to its simplicity in design, our PRVG framework can be applied in different testing schemes (sparse or dense grounding) and allows for efficient inference without any post-processing technique. In addition, we devise a robust proposal-level attention loss to guide the training of PRVG, which is invariant to moment duration and contributes to model convergence. We perform experiments on two video grounding benchmarks of ActivityNet Captions and TACoS, demonstrating that our PRVG can significantly outperform previous methods. We also perform in-depth studies to investigate the effectiveness of parallel regression paradigm on video grounding.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑