A Secure and Efficient Image Transmission Scheme Based on Two Chaotic Maps

Table 3

PSNR (dB) of 2DCS-ETC and SIT-SS under different sampling ratios.

Image	Scheme	Sampling ratio
		0.1	0.2	0.3	0.4	0.5	0.6	0.7	0.8	0.9
Lena	2DCS-ETC	25.1608	30.7238	33.7894	36.3407	38.5169	39.0429	40.3088	41.1759	41.7017
	SIT-SS	25.5232	30.6675	33.7680	36.3926	38.6439	40.4935	42.6165	44.9562	47.9543
Barbara	2DCS-ETC	22.0135	25.8589	28.8967	31.7166	34.2147	35.6315	37.3399	39.0916	40.2334
	SIT-SS	22.1990	25.8260	28.8175	31.6593	34.1841	36.4853	38.8797	41.5256	45.0071
Boats	2DCS-ETC	24.6290	29.7913	32.8112	35.3011	37.4047	38.0778	39.1809	40.3438	41.5691
	SIT-SS	24.1095	29.6903	32.8657	35.3405	37.4213	39.3371	41.3561	43.5876	46.6325
Cameraman	2DCS-ETC	22.3125	28.7665	31.8389	34.2630	36.4953	36.9751	38.2231	39.0237	39.7931
	SIT-SS	21.8324	28.7046	31.8201	34.2575	36.4449	38.6534	40.9500	43.3287	46.3889
Foreman	2DCS-ETC	29.5930	35.8537	38.1558	38.5413	39.4111	39.8570	40.2641	40.3616	40.6835
	SIT-SS	29.7572	35.7866	38.1025	39.8524	41.4978	42.9477	44.5395	46.3175	48.4910
House	2DCS-ETC	28.9899	34.1209	36.0911	37.5883	38.9428	39.1408	40.0489	41.1202	42.1401
	SIT-SS	28.3764	34.1188	36.1386	37.5654	38.9717	40.3546	42.0492	44.1757	47.0669
Monarch	2DCS-ETC	22.3624	29.0054	32.5729	35.6175	37.9890	38.1359	39.3164	40.0515	40.9473
	SIT-SS	22.0071	28.8123	32.6323	35.3864	37.8005	39.9611	42.1377	44.5657	47.4934
Parrots	2DCS-ETC	25.9860	33.0968	35.7941	37.8344	38.0873	39.1139	39.7870	40.3589	40.6380
	SIT-SS	25.7881	32.9618	35.6443	37.7954	39.5943	41.2956	43.0655	45.0295	47.6101

Each bold value means that one of the two compared schemes has a higher PSNR value than the other.