Robust Image Hashing Based on Cool and Warm Hue and Space Angle

Table 1

Attack setting in robustness experiment.

Operation	Parameter	Parameter values
JPEG compression	Quality	30, 40, ……, 100
Brightness adjustment	Level	−20, −10, 10, 20
Contrast adjustment	Level	−20, −10, 10, 20
Salt & pepper	Noise level	0.002, 0.004, ……, 0.01
Image resizing	Ratio	0.6, 0.8, 1.2, 1.4, 1.6, 1.8
3 × 3 Gaussian filter	Standard deviation	0.1, 0.2, ……, 1
Rotation	Angle	1, 2, 3, ……, 7, 8
Watermark embedding	Transparency	3, 4, ……, 7, 8
Gamma correction	Gamma	0.75, 0.9, 1.1, 1.25
speckle	Noise variance	0.002, 0.004, ……, 0.01