HybridGT: An Integration of Graph Transformer and LSTM for Effective Hyperspectral Band Selection

Hyperspectral imagery has a high-dimensional curse due to numerous spectral bands. Band selection (BS) is crucial for efficiently reducing dimensionality, retaining only essential bands containing valuable information. However, deep learning-based techniques have gained more attention through trained networks for band selection. Recently, graph-based learning has been extensively used in hyperspectral imagery, revealing intrinsic data relationships. This article presents a novel hybrid approach for hyperspectral band selection, addressing the curse of dimensionality in hyperspectral imagery (HSI). Integrating Long Short Term Memory (LSTM) and Graph Transformer (GT), the method employs Bi-dimensional Empirical Mode Decomposition (BEMD) for spatial data enhancement. Using transfer learning, we explore a ResNet-50 deep network to identify optimal intrinsic mode functions (IMFs). The final band subset will be obtained by concatenating the features extracted from the graph transformer and LSTM networks from selected IMFs and residual IMF, respectively. The proposed HybridGT-BS technique surpasses state-of-the-art methods in classification accuracy across three well-known HSI datasets - IP-Indian Pines, SA-Salinas, and PU-PaviaU. With the support of experimental results, the proposed technique significantly outperforms the classification accuracy with the best bands of the HSIs.