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

Table 6

Resistance comparison against noise attacks (BER).

Attack type	Proposed scheme			Scheme [19]	Scheme [20]	Scheme [24]
	1 image each group	3 images each group	5 images each group
Salt&peppers noise (d = 0.01)	0.0190	0.0099	0.0090	0.0333	0.0187	0.0394
Salt and peppers noise(d = 0.02)	0.0276	0.0142	0.0122	0.0480	0.0273	0.0571
Gaussian noise (d = 0.001)	0.0349	0.0194	0.0167	0.0142	0.0087	0.0220
Gaussian noise (d = 0.005)	0.0347	0.0189	0.0166	0.0304	0.0188	0.0476
Gaussian noise (d = 0.01)	0.0346	0.0191	0.0160	0.0434	0.0260	0.0671