论文标题
多级图形卷积网络,具有自动图学习,用于高光谱图像分类
Multi-Level Graph Convolutional Network with Automatic Graph Learning for Hyperspectral Image Classification
论文作者
论文摘要
如今,深度学习方法,尤其是图形卷积网络(GCN),在高光谱图像(HSI)分类中表现出了令人印象深刻的性能。但是,当前基于GCN的方法将图形结构和图像分类视为两个独立的任务,这通常会导致次优性能。这些方法的另一个缺陷是,它们主要集中于建模图节点之间的局部成对重要性,而缺乏捕获HSI的全局上下文信息的能力。在本文中,我们为HSI分类提出了一种具有自动图学习方法(MGCN-AGL)的多级GCN,该方法可以自动在本地和全局级别学习图形信息。通过采用注意机制来表征空间相邻区域之间的重要性,可以自适应地合并最相关的信息以做出决策,这有助于编码空间上下文以在本地层面形成图形信息。此外,我们利用多个途径进行局部级别的图形卷积,以利用HSI各种空间上下文的优点并增强生成的表示的表达能力。为了重建全球上下文关系,我们的MGCN-AGL根据图像区域之间的远距离依赖关系,基于在局部层面产生的表达性表示。然后,可以沿着连接遥远区域的重建图边缘执行推理。最后,多级信息被自适应地融合以生成网络输出。通过这种方式,可以将图形学习和图像分类集成到统一的框架中并相互受益。已经在三个现实世界中的高光谱数据集上进行了广泛的实验,这些数据集显示出胜过最新方法。
Nowadays, deep learning methods, especially the Graph Convolutional Network (GCN), have shown impressive performance in hyperspectral image (HSI) classification. However, the current GCN-based methods treat graph construction and image classification as two separate tasks, which often results in suboptimal performance. Another defect of these methods is that they mainly focus on modeling the local pairwise importance between graph nodes while lack the capability to capture the global contextual information of HSI. In this paper, we propose a Multi-level GCN with Automatic Graph Learning method (MGCN-AGL) for HSI classification, which can automatically learn the graph information at both local and global levels. By employing attention mechanism to characterize the importance among spatially neighboring regions, the most relevant information can be adaptively incorporated to make decisions, which helps encode the spatial context to form the graph information at local level. Moreover, we utilize multiple pathways for local-level graph convolution, in order to leverage the merits from the diverse spatial context of HSI and to enhance the expressive power of the generated representations. To reconstruct the global contextual relations, our MGCN-AGL encodes the long range dependencies among image regions based on the expressive representations that have been produced at local level. Then inference can be performed along the reconstructed graph edges connecting faraway regions. Finally, the multi-level information is adaptively fused to generate the network output. In this means, the graph learning and image classification can be integrated into a unified framework and benefit each other. Extensive experiments have been conducted on three real-world hyperspectral datasets, which are shown to outperform the state-of-the-art methods.