Robust and Fragile Medical Image Watermarking: A Joint Venture of Coding and Chaos Theories

Table 9

Received hash after various attacks.

Attack type	Attack parameter	Recovered hash
Salt and pepper noise	Variance 0.02	a16c4d382706e5a92f838ea64254c83a
	Variance 0.03	82706e5a9254cf838ea642a16c4d383a
	Variance 0.05	f86e5a9254c8338ea642a16c4d38270a
	Variance 0.2	d382706e5a838ea642a16c492f54c83a
Speckle noise	Variance 0.02	834d3827f068ea642a16ce5a9254c83a
	Variance 0.03	f38ea642a54c8316c4d8382706e5a92a
	Variance 0.05	8ea642a16c4d38270f836e5a9254c83a
	Variance 0.2	f83d83382706e5a9254c8ea642a16c4a
Gaussian noise	Variance 0.02	ea5a9254c8642a16c4d382706f838e3a
	Variance 0.05	fa16c4d382706e5838ea642a9254c83a
Median filtering	Window size 3 × 3	8ea642a16c4d382f83706e5a9254c83a
	Window size 5 × 5	f8 ea642a16c4d38382706e5a9254c83a
	Window size 7 × 7	f8c454c83d382706e5a9238ea642a16a
Tampering	9 bits	f838ea69254ca16c4d382706e5a83abb
	18 bits	f42a16c4d3829838ea6706e5a254bab01
Rotation	2 degrees	8a642a16c4d382f83706e5a9e254c83a
	8 degrees	fc4d38382706e5a9254c838ea642a16a