Hyperspectral and LiDAR Data Classification Using Joint CNNs and Morphological Feature Learning

Convolutional neural networks (CNNs) have been extensively utilized for hyperspectral image (HSI) and light detection and ranging (LiDAR) data classification. However, CNNs have not been much explored for joint HSI and LiDAR image classification. Therefore, this article proposes a joint feature learning (HSI and LiDAR) and fusion mechanism using CNN and spatial morphological blocks, which generates highly accurate land-cover maps. The CNN model comprises three Conv3D layers and is directly applied to the HSIs for extracting discriminative spectral-spatial feature representation. On the contrary, the spatial morphological block is able to capture the information relevant to the height or shape of the different land-cover regions from LiDAR data. The LiDAR features are extracted using morphological dilation and erosion layers that increase the robustness of the proposed model by considering elevation information as an additional feature. Finally, both the obtained features from CNNs and spatial morphological blocks are combined using an additive operation prior to the classification. Extensive experiments are shown with widely used HSIs and LiDAR datasets, i.e., University of Houston (UH), Trento, and MUUFL Gulfport scene. The reported results show that the proposed model significantly outperforms traditional methods and other state-of-the-art deep learning models. The source code for the proposed model will be made available publicly at https://github.com/AnkurDeria/HSI+LiDAR.