Spectral–Spatial Residual Graph Attention Network for Hyperspectral Image Classification

Abstract

Hyperspectral images (HSIs) not only possess abundant spectral features but also present a detailed spatial distribution of land cover, and they have significant advantages in the fine classification of ground materials. Recently, using convolutional neural networks (CNNs) to extract spectral–spatial features has become an effective way for HSI classification. However, conventional convolution kernels learn features from fixed regular square regions, and rich spatial information has not been effectively explored. In this letter, an end-to-end model named spectral–spatial residual graph attention network (S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> RGANet) is developed for HSI classification, and it has two crucial elements, including spectral residual and graph attention convolution modules. At first, two spectral residual modules are employed to capture discriminant spectral features. Then, graphs are constructed to reveal the relationship between points in local neighborhoods. By graph attention mechanism, local spatial information is adaptively aggregated from neighboring nodes. Experiments on two public HSI datasets demonstrate that the S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> RGANet is significantly superior to some state-of-the-art (SOTA) methods with limited training samples.