Na Li

h-index7
2papers
347citations

2 Papers

2.0CVMay 13, 2024
Support-Query Prototype Fusion Network for Few-shot Medical Image Segmentation

Xiaoxiao Wu, Zhenguo Gao, Xiaowei Chen et al.

In recent years, deep learning based on Convolutional Neural Networks (CNNs) has achieved remarkable success in many applications. However, their heavy reliance on extensive labeled data and limited generalization ability to unseen classes pose challenges to their suitability for medical image processing tasks. Few-shot learning, which utilizes a small amount of labeled data to generalize to unseen classes, has emerged as a critical research area, attracting substantial attention. Currently, most studies employ a prototype-based approach, in which prototypical networks are used to construct prototypes from the support set, guiding the processing of the query set to obtain the final results. While effective, this approach heavily relies on the support set while neglecting the query set, resulting in notable disparities within the model classes. To mitigate this drawback, we propose a novel Support-Query Prototype Fusion Network (SQPFNet). SQPFNet initially generates several support prototypes for the foreground areas of the support images, thus producing a coarse segmentation mask. Subsequently, a query prototype is constructed based on the coarse segmentation mask, additionally exploiting pattern information in the query set. Thus, SQPFNet constructs high-quality support-query fused prototypes, upon which the query image is segmented to obtain the final refined query mask. Evaluation results on two public datasets, SABS and CMR, show that SQPFNet achieves state-of-the-art performance.

4.4IVJun 21, 2021
Applying VertexShuffle Toward 360-Degree Video Super-Resolution on Focused-Icosahedral-Mesh

Na Li, Yao Liu

With the emerging of 360-degree image/video, augmented reality (AR) and virtual reality (VR), the demand for analysing and processing spherical signals get tremendous increase. However, plenty of effort paid on planar signals that projected from spherical signals, which leading to some problems, e.g. waste of pixels, distortion. Recent advances in spherical CNN have opened up the possibility of directly analysing spherical signals. However, they pay attention to the full mesh which makes it infeasible to deal with situations in real-world application due to the extremely large bandwidth requirement. To address the bandwidth waste problem associated with 360-degree video streaming and save computation, we exploit Focused Icosahedral Mesh to represent a small area and construct matrices to rotate spherical content to the focused mesh area. We also proposed a novel VertexShuffle operation that can significantly improve both the performance and the efficiency compared to the original MeshConv Transpose operation introduced in UGSCNN. We further apply our proposed methods on super resolution model, which is the first to propose a spherical super-resolution model that directly operates on a mesh representation of spherical pixels of 360-degree data. To evaluate our model, we also collect a set of high-resolution 360-degree videos to generate a spherical image dataset. Our experiments indicate that our proposed spherical super-resolution model achieves significant benefits in terms of both performance and inference time compared to the baseline spherical super-resolution model that uses the simple MeshConv Transpose operation. In summary, our model achieves great super-resolution performance on 360-degree inputs, achieving 32.79 dB PSNR on average when super-resoluting 16x vertices on the mesh.