Image Robust Watermarking Method Based on DWT-SVD Transform and Chaotic Map

Table 4

Attack types and descriptions.

Index	Description of the attack
1	Attack free
2	Salt and pepper noise with a noise density of 0.01
3	Salt and pepper noise with a noise density of 0.1
4	Salt and pepper noise with a noise density of 0.3
5	Gaussian noise with a variance of 0.01
6	Gaussian noise with a variance of 0.1
7	Gaussian noise with a variance of 0.3
8	Speckle noise with a variance of 0.05
9	Speckle noise with a variance of 0.1
10	Speckle noise with a variance of 0.3
11	Cropping 25% rows
12	Cropping 50% rows
13	Counter-clockwise rotation by 45°
14	Counter-clockwise rotation by 60°
15	JPEG compression with a quality factor of 80
16	JPEG compression with a quality factor of 60
17	Median filtering with a window size of 3 × 3
18	Median filtering with a window size of 5 × 5
19	Average filtering with a window size of 3 × 3
20	Average filtering with a window size of 5 × 5
21	Sharpening
22	Brightening by 50%
23	Darkening by 30%
24	Histogram equalization