Hyperspectral and multispectral image fusion via residual selective kernel attention-based U-net

The fusion of low-resolution hyperspectral image (LR-HSI) and high-resolution multispectral image (HR-MSI) is a crucial technology for producing high-resolution hyperspectral images. Most existing image fusion algorithms based on deep learning do not fully utilize the ability of neural network to extract and process multi-scale features, which leads to the problem of difficulty in fully learning features and ambiguity of features. In order to overcome these issues, a residual selective kernel attention-based U-net named RSKAU-net is designed for LR-HSI and HR-MSI fusion. RSKAU-net is constructed by a residual selective kernel module with an attention mechanism and a channel attention block. The residual selective kernel attention-based (RSKA) module is designed to process images of different resolutions, which adaptively extracts multi-scale features and efficiently emphasizes significant features through the attention mechanism. The channel attention (CA) module retains important spectral information by assigning different weights to each channel of LR-HSI. The proposed network can enhance the spatial information of LR-HSI while preserving its spectral information. Meanwhile, it effectively fuses the features from the source image to obtain the HR-HSI with rich details. The experimental results demonstrate that the proposed network has advantages in terms of both visual effect and objective quantitative indices when compared to existing HSI-MSI fusion approaches.