Fig. 1. Structure of improved RetinaNet

Fig. 2. Structure of DenseNet

Fig. 3. Network structure of dense block

Fig. 4. Structure of CBAM

Fig. 5. Structure of CAM

Fig. 6. Structure of SAM

Fig. 7. Structure of PFPN

Fig. 8. Sample diagram of dataset

Fig. 9. Loss value change curve

Fig. 10. Comparison of accuracy of each category

Fig. 11. Comparison of detection results. (a) Detection result of original algorithm; (b) detection result of improved algorithm