FPIseg: Iterative segmentation network based on feature pyramid for few-shot segmentation

Few-shot segmentation (FSS) enables rapid adaptation to the segmentation task of unseen-classes object based on a few labelled support samples. Currently, the focal point of research in the FSS field is to align features between support and query images, aiming to improve the segmentation performance. However, most existing FSS methods implement such support/query alignment by solely leveraging middle-level feature for generalization, ignoring the category semantic information contained in high-level feature, while pooling operation inevitably lose spatial information of the feature. To alleviate these issues, the authors propose the Iterative Segmentation Network Based on Feature Pyramid (FPIseg), which mainly consists of three modules: Feature Pyramid Fusion Module (FPFM), Region Feature Enhancement Module (RFEM), and Iterative Optimization Segmentation Module (IOSM). Firstly, FPFM fully utilizes the foreground information from the support image to implement support/query alignment under multi-scale, multi-level semantic backgrounds. Secondly, RFEM enhances the foreground detail information of aligned feature to improve generalization ability. Finally, ISOM iteratively segments the query image to optimize the prediction result and improve segmentation performance. Extensive experiments on the PASCAL-5(i) and COCO-20(i) datasets show that FPIseg achieves considerable segmentation performance under both 1-shot and 5-shot settings.