Cryptography Reference
In-Depth Information
(a) (b)
(c) (d)
Fig. 11.15.
The rotated watermarked images. (a) Rotation by 0.5
◦
in the clockwise
direction. (b) Rotation by 0.5
◦
in the counter-clockwise direction. (c) Rotation by
1
◦
in the clockwise direction. (d) Rotation by 1
◦
in the counter-clockwise direction.
(a) (b) (c) (d)
(e) (f) (g) (h)
Fig. 11.16.
The watermarks extracted from rotated watermarked images. (a) The
robust watermark extracted from Fig. 11.15(a), NHS = 0.805. (b) The semi-fragile
watermark extracted from Fig. 11.15(a), NHS = 0.063. (c) The robust watermark
extracted from Fig. 11.15(b), NHS = 0.783. (d) The semi-fragile watermark ex-
tracted from Fig. 11.15(b), NHS = 0.067. (e) The robust watermark extracted
from Fig. 11.15(c), NHS = 0.724. (f) The semi-fragile watermark extracted from
Fig. 11.15(c), NHS = 0.047. (g) The robust water-mark extracted from Fig. 11.15(d),
NHS = 0.713. (h) The semi-fragile watermark extracted from Fig. 11.15(d), NHS =
0.047.
