MAST: Video Polyp Segmentation with a Mixture-Attention Siamese Transformer
Geng Chen, Junqing Yang, Xiaozhou Pu, Ge-Peng Ji, Huan Xiong, Yongsheng Pan, Hengfei Cui, Yong Xia
TL;DR
MAST tackles video polyp segmentation by jointly encoding paired frames with a Siamese transformer and enriching their representations through a novel mixture-attention mechanism that combines inter-frame mutual-attention with intra-frame self-attention. The architecture uses two parallel decoders to generate segmentation maps and is trained with a hybrid BCE-IoU loss across multi-level outputs. On the SUN-SEG benchmark, MAST delivers state-of-the-art performance while maintaining competitive computation and parameter efficiency, with ablations confirming the effectiveness of both the Siamese transformer and mixture-attention modules. The method’s ability to leverage long-range spatio-temporal cues improves segmentation accuracy for challenging polyps and supports more reliable VPS in clinical workflows.
Abstract
Accurate segmentation of polyps from colonoscopy videos is of great significance to polyp treatment and early prevention of colorectal cancer. However, it is challenging due to the difficulties associated with modelling long-range spatio-temporal relationships within a colonoscopy video. In this paper, we address this challenging task with a novel Mixture-Attention Siamese Transformer (MAST), which explicitly models the long-range spatio-temporal relationships with a mixture-attention mechanism for accurate polyp segmentation. Specifically, we first construct a Siamese transformer architecture to jointly encode paired video frames for their feature representations. We then design a mixture-attention module to exploit the intra-frame and inter-frame correlations, enhancing the features with rich spatio-temporal relationships. Finally, the enhanced features are fed to two parallel decoders for predicting the segmentation maps. To the best of our knowledge, our MAST is the first transformer model dedicated to video polyp segmentation. Extensive experiments on the large-scale SUN-SEG benchmark demonstrate the superior performance of MAST in comparison with the cutting-edge competitors. Our code is publicly available at https://github.com/Junqing-Yang/MAST.
