A Strong Robust Zero-Watermarking Scheme Based on Shearlets’ High Ability for Capturing Directional Features

Table 3

The values of distorted host images and values of extracted watermarks after JPEG compressing.

Host image	JPEG20	JPEG30	JPEG40	JPEG60	JPEG70
	SSIM/NC	SSIM/NC	SSIM/NC	SSIM/NC	SSIM/NC
Boat	0.90/0.9961	0.93/0.9987	0.94/0.9980	0.98/0.9948	0.99/0.9980
Goldhill	0.84/0.9830	0.89/0.9869	0.90/0.9882	0.97/0.9961	0.99/0.9980
Baboon	0.78/0.9671	0.83/0.9830	0.85/0.9829	0.89/0.9889	0.92/0.9830
Barbara	0.87/0.9974	0.91/0.9980	0.93/0.9974	0.98/0.9993	0.99/1.0000
Peppers	0.83/0.9993	0.86/0.9993	0.87/0.9987	0.89/1.0000	0.90/1.0000
Man	0.84/0.9882	0.88/0.9928	0.90/0.9935	0.92/0.9954	0.94/0.9948