Multilevel Progressive Network With Nonlocal Channel Attention for Hyperspectral Image Super-Resolution
Jianwen Hu, Yaoting Liu, Xudong Kang, Shaosheng Fan
Abstract
Deep convolutional neural networks (CNNs) have made great progress in the super-resolution (SR) of hyperspectral images (HSIs). However, most methods utilize convolution to explore local features, and global features are ignored. It is expected that combining non-local mechanism with CNN will improve the performance of HSI SR. This paper presents a multi-level progressive HSI SR network. The dense non-local and local block (DNLB) is constructed to combine local and global features, which are used to reconstruct super-resolution images at each level. Due to the high dimension of HSI, original non-local methods produce memory-expensive attention maps. We develop a non-local channel attention block to extract the global features of HSIs efficiently. Spatial-spectral gradient is injected in the non-local attention block to obtain better details. Furthermore, the progressive learning mode based multi-level network is proposed to reconstruct HSI with fine details. A number of experiments demonstrate that our method can reconstruct hyperspectral images more accurately than existing methods.