Juan Wang

Winter wheat is one of the most important food crops in China, and it is of great significance to ensure national food security. The accurate extraction of wheat-growing areas is a prerequisite for growth assessments, stress monitoring, and yield assessments. In this study, GF-6 (8 m resolution) and Sentinel-2 (10 m resolution) remote sensing images were used to create datasets for the accurate extraction of winter-wheat growing areas by improving the U-Net model. First, U-Net was used as the base network to extract features, and then the convolutional block attention module (CBAM) was embedded in the basic convolutional units in the coding and decoding layers of the network to enhance or suppress the features to improve the feature-expression capability of the model, and to finally complete the end-to-end winter-wheat planting-area extraction. SegNet, DeepLabV3+, and U-Net-CBAM were selected as the comparison models, and they were tested using the test set in the Sentinel-2 dataset. The precision of the U-Net-CBAM model trained on the GF-6 dataset was 84.92%, the MIoU was 77.1%, the recall was 88.28%, the overall precision (OA) was 91.64%, and the F₁ was 86.45%. For training on Sentinel-2 dataset, those values were: 90.06% for precision, 83.18% for MIoU, 90.78% for recall, 93.93% for OA, and 90.52% for F₁, which showed significantly better results than those of the comparison models, indicating that U-Net-CBAM improved the accuracy of winter-wheat area extraction. It also showed that the segmentation performance of the training and test sets from different datasets was much lower than the segmentation performance from the same dataset.