Classification Based on Hyperspectral Image and LiDAR Data with Contrastive Learning

This study proposes a semi-supervised method using multimodality data with contrastive learning to improve the classification accuracy for hyperspectral images ( HSI) and light and detection ranging ( LiDAR) data in the case of a few labeled samples. The proposed method conducts contrastive learning using HSI and LiDAR data without labels, which helps to build the relationship between the spatial features of the two data. Thereafter, their spatial features can be extracted by the model. We designed a network combining the convolution and Transformer modules, which allows the model to extract the local features for establishing a global interaction relationship. We conducted experiments on contrastive learning on the Houston 2013 and Trento datasets. The results show that the classification accuracy of the proposed method is higher than that of other multisource data fusion classification methods. On the Houston 2013 dataset, the classification accuracy of the proposed method is 20. 73 percentage points higher than that of the comparison method when the number of labeled samples is five. On the Trento dataset, the classification accuracy of the proposed method is 8. 35 percentage points higher than that of the comparison method when the number of labeled samples is two.