| International Journal of Applied Information Systems |
| Foundation of Computer Science (FCS), NY, USA |
| Volume 13 - Number 3 |
| Year of Publication: 2026 |
| Authors: Joseph Ngwa, Elie Fute Tagne, Nde Nguti |
10.5120/ijca247c5035158a
|
Joseph Ngwa, Elie Fute Tagne, Nde Nguti . An Enhanced U-Net Architecture with Attention Gates and Atrous Spatial Pyramid Pooling for Building Segmentation in Aerial Imagery. International Journal of Applied Information Systems. 13, 3 ( Jul 2026), 33-47. DOI=10.5120/ijca247c5035158a
Accurate building segmentation from high-resolution aerial imagery remains challenging due to variations in building size, shape, background clutter, and class imbalance. This study proposes an Enhanced U-Net architecture for automatic building extraction using the Massachusetts Buildings Dataset and the Inria Aerial Image Labeling Dataset. The proposed model extends the conventional U-Net by incorporating a deeper encoder with Batch Normalization, Attention Gates (AGs) in decoder skip connections, and an Atrous Spatial Pyramid Pooling (ASPP) module for multi-scale contextual feature extraction. Different ASPP dilation-rate configurations were investigated, with dilation rates of 3, 6, and 9 yielding the best performance. To handle the high spatial resolution of the imagery, a patch-based training strategy with 50% overlap was adopted, using patch sizes of 256 × 256 and 512 × 512 for the Massachusetts and Inria datasets, respectively. The model was optimized using a hybrid Binary Cross-Entropy (BCE) and Dice loss function to balance pixel-level classification and region-overlap accuracy. Experimental results demonstrate that the proposed Enhanced U-Net outperformed U-Net, DeepLabv3+, and HRNet. On the Massachusetts Buildings Dataset, it achieved an IoU of 0.737 and an F1-score of 0.848. On the Inria dataset, it achieved an IoU of 0.799 and an F1-score of 0.888. These results demonstrate the effectiveness and generalization capability of the proposed architecture for aerial building segmentation.