One-shot object detection aims at detecting novel objects according to merely one given instance. With extreme data scarcity, current approaches explore various feature fusions to obtain directly transferable meta-knowledge. Yet, their performances are often unsatisfactory. In this paper, we attribute this to inappropriate correlation methods that misalign query-support semantics by overlooking spatial structures and scale variances. Upon analysis, we leverage the attention mechanism and propose a simple but effective architecture named Semantic-aligned Fusion Transformer (SaFT) to resolve these issues. Specifically, we equip SaFT with a vertical fusion module (VFM) for cross-scale semantic enhancement and a horizontal fusion module (HFM) for cross-sample feature fusion. Together, they broaden the vision for each feature point from the support to a whole augmented feature pyramid from the query, facilitating semantic-aligned associations. Extensive experiments on multiple benchmarks demonstrate the superiority of our framework. Without fine-tuning on novel classes, it brings significant performance gains to one-stage baselines, lifting state-of-the-art results to a higher level.

研究了在数据稀缺的情况下，单次目标检测的问题，提出了一个效果良好的基于注意力机制的框架，名为Semantic-aligned Fusion Transformer (SaFT)，采用竖直和水平融合模块实现跨尺度和跨样本特征的融合，通过语义对齐的注意力机制大幅提高性能，使得基于目前现有的数据训练的一阶段的检测基线的性能得到了显著提升。

语义对齐融合transformer用于一阶段物体检测