Identifying robust and accurate correspondences across images is a fundamental problem in computer vision that enables various downstream tasks. Recent semi-dense matching methods emphasize the effectiveness of fusing relevant cross-view information through Transformer. In this paper, we propose several improvements upon this paradigm. Firstly, we introduce affine-based local attention to model cross-view deformations. Secondly, we present selective fusion to merge local and global messages from cross attention. Apart from network structure, we also identify the importance of enforcing spatial smoothness in loss design, which has been omitted by previous works. Based on these augmentations, our network demonstrate strong matching capacity under different settings. The full version of our network achieves state-of-the-art performance among semi-dense matching methods at a similar cost to LoFTR, while the slim version reaches LoFTR baseline's performance with only 15% computation cost and 18% parameters.

本文提出了基于变换器的半密集匹配方法，引入了基于仿射的局部注意力和选择性融合来模拟跨视图变形，并强调了损失设计中的空间平滑性的重要性，通过这些增强方法，我们的网络在不同设置下表现出很强的匹配能力。

基于仿射变换的可变形注意力和选择性融合用于半密匹配