Video Instance Segmentation via Multi-scale Spatio-temporal Split Attention Transformer

Omkar Thawakar, Mohamed bin Zayed University of Artificial Intelligence
Sanath Narayan, Inception Institute of Artificial Intelligence
Jiale Cao, Tianjin University, China
Hisham Cholakkal, Mohamed bin Zayed University of Artificial Intelligence
Muhammad Haris Khan, Mohamed bin Zayed University of Artificial Intelligence
Salman Khan, Mohamed bin Zayed University of Artificial Intelligence
Michael Felsberg, Linköping University, Sweden
Fahad Shahbaz Khan, Mohamed bin Zayed University of Artificial Intelligence & Linköping University, Sweden

Preprint: arXiv

Archived with thanks to arXiv

Preprint License: CC by 4.0

Uploaded 24 May 2022

Abstract

State-of-the-art transformer-based video instance segmentation (VIS) approaches typically utilize either single-scale spatio-temporal features or per-frame multi-scale features during the attention computations. We argue that such an attention computation ignores the multi-scale spatio-temporal feature relationships that are crucial to tackle target appearance deformations in videos. To address this issue, we propose a transformer-based VIS framework, named MS-STS VIS, that comprises a novel multi-scale spatio-temporal split (MS-STS) attention module in the encoder. The proposed MS-STS module effectively captures spatio-temporal feature relationships at multiple scales across frames in a video. We further introduce an attention block in the decoder to enhance the temporal consistency of the detected instances in different frames of a video. Moreover, an auxiliary discriminator is introduced during training to ensure better foreground-background separability within the multi-scale spatio-temporal feature space. We conduct extensive experiments on two benchmarks: Youtube-VIS (2019 and 2021). Our MS-STS VIS achieves state-of-the-art performance on both benchmarks. When using the ResNet50 backbone, our MS-STS achieves a mask AP of 50.1%, outperforming the best reported results in literature by 2.7% and by 4.8% at higher overlap threshold of AP75, while being comparable in model size and speed on Youtube-VIS 2019 val. set. When using the Swin Transformer backbone, MS-STS VIS achieves mask AP of 61.0% on Youtube-VIS 2019 val. set. Our code and models are available at https://github.com/OmkarThawakar/MSSTS-VIS. © 2022, CC BY.