Fig. 1. The optimal sampling point distribution map for different images (with 20% sampling rate). The white points are sampling points, and the black areas are non-sample points. (a) Lena image; (b) Boat image

Fig. 2. Circular sampling. (a) The priority sampling order, gradually decreasing from low frequency to high frequency priority;(b) The sampling trajectories generated by the circular sampling method at the sampling rate of 20%

Fig. 3. The sampling trajectories generated by Gaussian random sampling method at the sampling rate of 20%

Fig. 4. Test target image and its Fourier spectrum. (a) Resolution plate USAF-1951 binary image;(b) Baboon image; (c) Photographer image; (d) Rice image

Fig. 5. Resolution board sampling trajectories by four sampling methods with the sampling rates ranging from 5% to 25%. The white points are sampling points, and the black areas are non-sample points

Fig. 6. Reconstruction images of resolution plate by four sampling methods with the sampling rates ranging from 5% to 25%

Fig. 7. Photographer's sampling trajectories by four sampling methods with the sampling rates ranging from 5% to 25%

Fig. 8. Photographer's reconstructed images by four sampling methods with the sampling rates ranging from 5% to 25%

Fig. 9. Sampling trajectories of rice by four sampling methods with the sampling rates ranging from 5% to 25%

Fig. 10. Reconstructed images of rice by four sampling methods with the sampling rates ranging from 5% to 25%

Fig. 11. Sampling trajectories of baboon by four sampling methods with the sampling rates ranging from 5% to 25%

Fig. 12. Reconstructed images of baboon by four sampling methods with the sampling rates ranging from 5% to 25%

Fig. 13. R_PSN values of reconstructed images by four sampling strategies. (a) USAF-1951 binary image;(b) Photographer image; (c) Rice image; (d) Baboon image