Fig. 1. Comparison of gradient

Fig. 2. 8 neighborhood direction codes of point P

Fig. 3. Determined region for kernel estimation

Fig. 4. Schematic diagram of image expansion

Fig. 5. Multiple region for kernel estimation

Fig. 6. Flowchart of space-invariant image restoration

Fig. 7. Flowchart of space-variant image restoration

Fig. 8. Comparison of restoration results of degraded images of ground targets

Fig. 9. Comparison of PSNR and SSIM

Fig. 10. Comparison of restoration results of degraded images of real air and surface targets

Fig. 11. Results of space-variant image restoration