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

Table 9

Discrimination comparison (BER).

Attack type	Proposed scheme			Scheme [19]	Scheme [20]	Scheme [24]
	1 image each group	3 images each group	5 images each group
JPEG compression (QF = 20)	0.3315	0.3408	0.3283	0.1998	0.2232	0.3356
Rotation(−45°)	0.3314	0.3401	0.3276	0.1986	0.2229	0.3359
Scaling (0.3)	0.3408	0.3388	0.3241	0.1912	0.2280	0.3297
Scaling (3)	0.3310	0.3401	0.3275	0.1997	0.2237	0.3367
Salt and peppers noise (d = 0.05)	0.3323	0.3392	0.3281	0.2127	0.2249	0.3409
Gaussian noise(d = 0.005)	0.3317	0.3393	0.3283	0.2317	0.2320	0.3491