Cryptanalysis and Improvement of the Robust and Blind Watermarking Scheme for Dual Color Image

Table 2

Evaluation of the robustness of the watermarking scheme.

Attacks	Improved scheme				Original scheme
	Attacked image	PSNR (dB)	Extracted; watermark	NC	PSNR (dB)	NC
Brightness + 2		33.1662		0.9999	33.1664	1.0000
Sharpening		33.4241		0.983	33.424	0.9831
Mosaic 3 * 3		30.2472		0.9518	30.247	0.9519
Median filtering		28.8052		0.9093	28.8053	0.9095
Cropping 1		11.5489		0.9999	11.5491	0.9999
Cropping 2		14.0279		0.937	14.0276	0.9369
Rotating + 5°		14.683		0.7691	14.681	0.7687
Low pass filtering		28.4824		0.9991	28.4825	0.9991
Adding noise 4%		28.083		0.9971	28.0835	0.9971
JPEG 50%		30.8597		0.9791	30.8597	0.9792