CloudU-Netv2: A Cloud Segmentation Method for Ground-Based Cloud Images Based on Deep Learning

摘要

Accurately acquiring cloud information through cloud images segmentation is of great importance for weather forecasting, environmental monitoring, sites selection of observatory and analysis of climate evolution. In this paper, a cloud segmentation method based on deep learning, called CloudU-Netv2, is proposed to segment daytime and nighttime ground-based cloud images. The CloudU-Netv2 includes encoder, dual attention modules and decoder. The contributions in this paper are four folds as follows. Firstly, it replaces the ‘upsampling’ in CloudU-Net with ‘bilinear upsampling’. Secondly, position and channel attention modules are added to the structure to improve the discrimination ability of features’ representation. Thirdly, it chooses rectified Adam as the optimizer in the CloudU-Netv2 structure. Finally, we conduct ablation experiments on the key components of CloudU-Netv2 and compare with the existing four advanced methods using six evaluation metrics. Results show that the key components of the model play the pivotal role in improving the segmentation performance, and the proposed CloudU-Netv2 has the best segmentation performance for daytime and nighttime ground-based cloud images compared with four other methods.