Improved Chaos-Based Cryptosystem for Medical Image Encryption and Decryption

Table 8

PSNR, SSIM, and NC results between the original and the corresponding decrypted image under different intensities of salt and pepper noise.

Image	Data loss	Salt and pepper
	Intensity		0.009	0.01	0.05	0.09	0.1	0.5
Lena; 512 × 512 × 3	PSNR	39.51	37.96	35.68	32.66	29.89	28.67	26.61
	SSIM	0.982	0.969	0.967	0.856	0.765	0.748	0.479
	NC	0.988	0.980	0.979	0.899	0.828	0.814	0.557
Peppers; 512 × 512 × 3	PSNR	39.08	37.58	35.02	31.11	29.54	28.05	26.09
	SSIM	0.983	0.969	0.967	0.857	0.771	0.751	0.489
	NC	0.990	0.982	0.980	0.906	0.840	0.826	0.564
Baboon; 512 × 512 × 3	PSNR	39.81	38.20	36.93	32.81	30.27	28.83	26.82
	SSIM	0.977	0.959	0.957	0.821	0.722	0.701	0.458
	NC	0.992	0.987	0.986	0.931	0.878	0.867	0.521
3D ultrasound baby; 2844 × 4044 × 3	PSNR	40.92	38.40	37.98	35.90	31.34	29.89	26.92
	SSIM	0.936	0.902	0.894	0.713	0.623	0.604	0.420
	NC	0.994	0.991	0.990	0.949	0.907	0.897	0.496
3D scanner ankle; 1080 × 1920 x 3	PSNR	40.26	37.69	36.21	35.17	31.65	29.21	25.20
	SSIM	0.986	0.937	0.917	0.856	0.782	0.571	0.437
	NC	0.994	0.990	0.989	0.945	0.904	0.894	0.501
3D radiography; 2400 × 2956 × 3	PSNR	41.21	38.85	37.32	35.79	32.63	29.85	25.81
	SSIM	0.981	0.916	0.896	0.805	0.663	0.549	0.425
	NC	0.994	0.990	0.989	0.946	0.905	0.893	0.487
3D X-ray; 3816 × 2832 × 3	PSNR	40.26	38.47	36.96	34.98	31.75	28.72	25.34
	SSIM	0.985	0.979	0.968	0.871	0.782	0.766	0.421
	NC	0.976	0.963	0.945	0.883	0.769	0.747	0.453
3D CT-scan; 800 × 600 × 3	PSNR	40.64	38.35	36.45	34.66	30.74	27.76	25.17
	SSIM	0.979	0.973	0.841	0.795	0.632	0.473	0.437
	NC	0.979	0.968	0.946	0.891	0.787	0.761	0.507
1D ultrasound; 1200 × 700	PSNR	39.54	37.26	36.08	32.17	28.95	27.21	25.14
	SSIM	0.987	0.942	0.909	0.867	0.831	0.782	0.587
	NC	0.993	0.989	0.953	0.851	0.704	0.694	0.501
MRI; 456 × 456 × 1	PSNR	39.75	37.81	35.52	31.62	29.98	27.83	24.92
	SSIM	0.991	0.975	0.860	0.713	0.689	0.626	0.516
	NC	0.995	0.983	0.974	0.898	0.826	0.711	0.501
Endoscopy; 634 × 549	PSNR	39.67	38.14	37.32	35.23	31.07	29.17	25.72
	SSIM	0.984	0.924	0.887	0.812	0.674	0.589	0.477
	NC	0.995	0.987	0.982	0.943	0.910	0.879	0.513