Author Affiliations
1School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo, Henan 454000, China2PLA Strategic Support Force Information Engineering University, Zhengzhou, Henan 450001, Chinashow less
Fig. 1. Flow chart of building extraction based on SA-Net
Fig. 2. Schematic diagram of the SA-Net
Fig. 3. Schematic diagram of the RSPP
Fig. 4. Schematic diagram of the AFR module
Fig. 5. Two sets of example images. (a) WHU dataset; (b) Massachusetts dataset
Fig. 6. Diagram of the overlap strategy
Fig. 7. Segmentation results of WHU dataset by different models. (a) Image; (b) label; (c) U-Net; (d) MultiResUNet; (e) Res-UNet; (f) S-UNet; (g) USPP; (h) SA-Net
Fig. 8. Segmentation results of the Massachusetts dataset by different models. (a) Image; (b) label; (c) U-Net; (d) MultiResUNet; (e) Res-UNet; (f) S-UNet; (g) USPP; (h) SA-Net
Model | U-Net | USPP | S-UNet | Res-UNet | SA-Net | MultiResUNet |
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Parameter number /106 | 7.76 | 4.82 | 7.97 | 4.73 | 7.13 | 7.26 | Max batch size | 37 | 22 | 23 | 19 | 25 | 6 |
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Table 1. Number of parameters and the maximum number of batches of different models
Model | Batch size | Image size(pixel×pixel) | Graphic card | Video memory /G | IOU /% |
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U-Net (random cropping training) | 16 | 256×256 | RTX 2070 | 8 | 88.58 | U-Net (Ref. [15]) | 8 | 512×512 | Nvidia P6000 | 24 | 84.08 | U-Net (Ref. [4]) | 6 | 512×512 | Nvidia Titan XP | 12 | 86.80 |
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Table 2. Random sampling training and regular training results of different models in the WHU dataset
Parameter | WHU ariel dataset | Massachusetts dataset |
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Training image number (size) | 4736 (512 pixel×512 pixel) | 8631 (512 pixel×512 pixel) | Validation image number (size) | 4144 (256 pixel×256 pixel) | 144 (256 pixel×256 pixel) | Training epoch | 300 | 200 | Steps per epoch | 296 | 540 | Batch size | 16(6 for MultiResUNet) | 16(6 for MultiResUNet) | Iteration number | 296×300 | 540×200 | Padding size | 0 | 64 |
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Table 3. Experimental settings of WHU ariel dataset and Massachusetts dataset
Dataset | Model | Precision | Recall | IOU | F1 score |
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WHU | U-Net | 94.37 | 93.52 | 88.58 | 93.94 | USPP | 94.50 | 94.35 | 89.44 | 94.42 | MultiResUNet | 97.00 | 90.01 | 87.57 | 93.37 | S-UNet (Ref. [14]) | 95.20 | 93.00 | 88.80 | 94.09 | SR-FCN (Ref. [4]) | 94.40 | 93.90 | 88.90 | 94.15 | S-UNet | 94.74 | 93.77 | 89.14 | 94.25 | DeepLab V3+ (Ref. [4]) | 91.60 | 94.60 | 87.10 | 93.08 | Res-UNet | 92.71 | 93.90 | 87.44 | 93.30 | SA-Net | 95.27 | 93.80 | 89.62 | 94.53 | Massachusetts | U-Net | 85.84 | 81.18 | 71.60 | 83.44 | MultiResUNet | 93.22 | 66.84 | 63.74 | 77.86 | USPP | 88.50 | 79.37 | 71.95 | 83.69 | S-UNet | 86.05 | 81.50 | 71.99 | 83.71 | Res-UNet | 87.08 | 77.66 | 69.64 | 82.10 | Res-UNet (Ref. [11]) | 86.21 | 80.26 | 71.14 | 83.13 | JointNet (Ref. [11]) | 86.21 | 81.29 | 71.99 | 83.68 | SA-Net | 86.78 | 82.70 | 73.45 | 84.69 |
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Table 4. Quantitative evaluation results of different models on the WHU and Massachusetts datasets unit: %
Model | U-Net | USPP | S-UNet | Res-UNet | SA-Net | MultiResUNet |
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Training time | 10.7 | 11.8 | 12.8 | 13.4 | 13.3 | 35.1 |
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Table 5. Training time of different models on the WHU dataset unit: h
Dataset | Index | U-Net (base-line) | MIMO | RSPP | AFR | IOU | F1 score |
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WHU | 1 | Ö | | | | 88.58 | 93.94 | 2 | Ö | Ö | | | 89.37 | 94.38 | 3 | Ö | Ö | Ö | | 89.67 | 94.55 | 4 | Ö | Ö | Ö | Ö | 89.62 | 94.53 | Massachusetts | 1 | Ö | | | | 71.60 | 83.44 | 2 | Ö | Ö | | | 73.02 | 84.41 | 3 | Ö | Ö | Ö | | 73.06 | 84.44 | 4 | Ö | Ö | Ö | Ö | 73.45 | 84.69 |
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Table 6. Evaluation results of ablation experiments unit: %
Dataset | Model | Precision | Recall | IOU | F1 score |
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WHU | U-Net | 83.03 | 85.87 | 73.05 | 84.43 | USPP | 87.42 | 86.60 | 77.00 | 87.01 | S-UNet | 87.11 | 86.64 | 76.80 | 86.87 | SA-Net | 88.92 | 86.23 | 77.86 | 87.55 | Massachusetts | U-Net | 86.30 | 73.46 | 65.79 | 79.36 | USPP | 86.64 | 75.79 | 67.86 | 80.85 | S-UNet | 84.56 | 79.21 | 69.20 | 81.80 | SA-Net | 87.49 | 79.28 | 71.21 | 83.18 |
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Table 7. Experimental results of small sample conditions unit: %