Fig. 1. Spherically curved crystal imaging system. (a) Schematic diagram of the system; (b) image of the backlight detected in the experiment

Fig. 2. Theoretical values of the system performance parameters. (a) Magnification; (b) resolution

Fig. 3. Curves of spatial resolution and imaging efficiency as a function of backlight size

Fig. 4. Curves of spatial resolution at the center and edge of the spherically curved crystal

Fig. 5. Influence of the spherically curved crystal radius error on imaging performance. (a) Magnification; (b) resolution

Fig. 6. Grid imaging results and analysis. (a) 1500 mesh Cu grid imaging result; (b) ESF fitting results

Fig. 7. Grid imaging results and analysis. (a) 1500 mesh Cu grid imaging results; (b) relationship between resolution and distance away from the best imaging area

Fig. 8. Sample of lycorma delicatula

Fig. 9. Images of biological sample. (a) Monochromatic X-ray imaging results of the wings; (b) processing results of the Retinex algorithm

Fig. 10. Flow chart of Retinex algorithm