Fig. 1. Information extracted by the convolutional structure of each layer in CNN structure

Fig. 2. Generator network model for coarse-grained network

Fig. 3. Discriminator network model for coarse-grained network

Fig. 4. Discriminator network model for fine-grained network

Fig. 5. Extracted objects to be detected by tailoring

Fig. 6. Model of object detection network

Fig. 7. Part of dataset

Fig. 8. Loss function values for different models in coarse-grained network. (a) Discriminator network; (b) generator network

Fig. 9. Loss function values for different models in fine-grained network. (a) Discriminator network; (b) generator network

Fig. 10. Airplane images produced by fine-grained network

Fig. 11. Change in loss function value during the training process

Fig. 12. Part of detection results

Fig. 13. Loss function value curves during the training process. (a) With GAN for pretraining; (b) without GAN for pretraining

Fig. 14. Comparison of the mAP of different network models