A Robust Fractal Color Image Watermarking Algorithm

Table 1

Extracted watermarks (EW) and NCs after attacked by JPEG compression with the quality factors (QF) 15, 25, 35, 45, 55, 65, 75, and 85 on Lena, Barbara, and Peppers.

QF	15	25	35	45	55	65	75	85
Lena
EW
NC	0.6837	0.7656	0.8257	0.8969	0.9957	0.9995	1.0000	1.0000
Barbara
EW
NC	0.6320	0.6792	0.7510	0.8060	0.9529	0.9653	0.9882	0.9956
Peppers
EW
NC	0.4950	0.5752	0.6438	0.7336	0.9070	0.9241	0.9442	0.9529