A Global Spectral–Spatial Feature Learning Network for Semisupervised Hyperspectral Unmixing

Abstract

Neural networks have been widely applied in hyperspectral unmixing in the past few years. However, most networks only focus on extracting the spectral information or local spectral–spatial correlation of a single pixel. In order to further explore the spectral–spatial information of hyperspectral images (HSIs) and improve the effective use of spatial information in unmixing tasks, an end-to-end semisupervised unmixing network is proposed in this article. At the encoder, the dual branch network performs convolution operations along the spatial dimension and the spectral dimension, respectively, to realize the separated extraction of global spatial and spectral information; the spectral–spatial attention residual module then fuses the separated spectral–spatial features into the joint spectral–spatial information. The encoder is to realize mapping from high-dimensional spectral data to latent abundance representations. The decoder is a simple linear fully connected layer whose weight is fixed to a known spectral library to complete the reconstruction of the HSI. Experiments on two synthetic datasets and two real datasets demonstrate the superior performance of the proposed method, and prove the effectiveness of considering global spatial information in the unmixing task.

Keywords

• Hyperspectral unmixing (HU)
• feature extraction
• deep learning
• spectral–spatial
• attention mechanism