Fig. 1. Carrier image scaling and equal processing. (a) Hidden carrier 512×512; (b) carrier scaling 510×510; (c) hidden information170×170; (d) carrier equalization (170×170)×9

Fig. 2. Information image Arnold scrambling processing. (a) Hidden information original image; (b) 1st horizontal and vertical stagger; (c) 9th horizontal and vertical stagger; (d) 12th horizontal and vertical stagger

Fig. 3. Comparison of image processing effects between extreme value method and mean value method. (a) Hidden carrier image; (b) image processing effect of extreme value method; (c) image processing effect of mean value method

Fig. 4. Working principle of echo state network

Fig. 5. Carrier and information comparison after embedding/extraction. (a) Evenly divided carrier image with gray-level correlation order; (b) information image after scrambling; (c) hidden information carrier; (d) information image after extraction and inverse transformation C_N=0.9993

Fig. 6. Gaussian noise interference effect. (a) Original image; (b) σ=0.1; (c) σ=0.5; (d) σ=1.0; (e) σ=2.0; (f) σ=5.0

Fig. 7. Salt and pepper noise interference effect. (a) R_SN=1.0; (b) R_SN=0.8; (c) R_SN=0.6; (d) R_SN=0.4; (e) R_SN=0.2; (f) R_SN=0.0

Fig. 8. Geometric attack effect comparison. (a) Original image; (b) spin attack;(c) flip attack; (d) curve attack; (e) twist attack; (f) translation attack; (g) shrink attack; (h) amplification attack