A Polar Complex Exponential Transform-Based Zero-Watermarking for Multiple Medical Images with High Discrimination

Table 5

Resistance comparison against geometric attacks (BER).

Attack type	Proposed scheme			Scheme [19]	Scheme [20]	Scheme [24]
	1 image each group	3 images each group	5 images each group
Rotation (−3°)	0.0043	0.0040	0.0048	0.0131	0.0103	0.0129
Rotation (−5°)	0.0034	0.0030	0.0033	0.0076	0.0080	0.0085
Rotation (−10°)	0.0043	0.0038	0.0042	0.0045	0.0048	0.0058
Scaling (0.5)	0.0045	0.0041	0.0044	0.0046	0.0084	0.0060
Scaling (2)	0.0027	0.0022	0.0025	0.0011	0.0017	0.0014