A Simple Image Encryption Based on Binary Image Affine Transformation and Zigzag Process

Table 6

Correlation coefficients between two vertically, horizontally, and diagonally adjacent pixels in several nonmedical plain images and also in their corresponding encrypted images from database.

Image Name	Description	Correlation coefficients of original images			Correlation coefficients of cipher images
		Vert cor	Hor cor	Diag cor	Vert cor	Hor cor	Diag cor
4.1.01	Girl	0.96547	0.9737	0.94928	-2.94e−04	1.58e−03	5.41e−04
4.1.02	Couple	0.95615	0.93889	0.90658	2.09e−03	-1.85e−04	9.21e−04
4.1.03	Girl	0.91432	0.97598	0.89425	-4.05e−04	2.47e−03	4.50e−04
4.1.04	Girl	0.98476	0.96995	0.95805	5.88e−05	5.11e−04	-1.98e−03
4.1.05	House	0.95289	0.9781	0.94157	-3.75e−04	-1.20e−03	2.38e−04
4.1.06	Tree	0.9441	0.96695	0.9285	-2.87e−03	-3.22e−03	5.65e−04
4.1.07	Jelly beans	0.98233	0.9787	0.96461	1.58e−03	-4.40e−03	-2.56e−03
4.1.08	Jelly beans	0.97553	0.97258	0.95246	3.56e−03	-7.71e−04	-6.16e−04
4.2.01	Splash	0.9915	0.98399	0.98054	2.25e−04	-1.19e−03	-8.85e−04
4.2.02	Girl (tiffany)	0.94097	0.93826	0.91514	-2.56e−03	-8.88e−04	1.63e−03
4.2.03	Mandrill (a.k.a. Baboon)	0.75486	0.86269	0.72324	1.36e−03	-5.84e−04	-4.73e−04
4.2.04	Girl (lena. or lena)	0.98485	0.97159	0.9635	9.09e−05	-2.57e−04	-4.52e−04
4.2.05	Airplane (F-16)	0.96394	0.96616	0.94106	-7.67e−04	2.28e−03	-9.57e−05
4.2.06	Sailboat on lake	0.97003	0.97368	0.95768	9.21e−04	5.35e−04	3.48e−04
4.2.07	Peppers	0.97788	0.97567	0.96806	3.40e−03	-1.47e−03	-3.18e−04
5.1.09	Moon surface	0.93093	0.89444	0.88385	3.49e−03	2.34e−03	-1.91e−03
5.1.10	Aerial	0.85731	0.90234	0.80779	3.27e−04	-1.65e−03	1.42e−03
5.1.11	Airplane	0.93722	0.95697	0.91391	6.44e−04	-1.97e−03	-1.84e−03
5.1.12	Clock	0.97373	0.95613	0.93755	-1.33e−03	-1.34e−03	1.06e−03
5.1.13	Resolution chart	0.86678	0.87242	0.75713	1.78e−03	8.89e−04	-2.11e−04
5.1.14	Chemical plant	0.89647	0.94525	0.8672	8.69e−04	-3.28e−03	-2.29e−03
5.2.08	Couple	0.89244	0.93684	0.85528	1.14e−04	9.13e−04	1.12e−03
5.2.09	Aerial	0.85803	0.89863	0.80248	-1.94e−03	-2.45e−04	-6.92e−04
5.2.10	Stream and bridge	0.92548	0.93854	0.89787	1.79e−03	1.26e−03	8.91e−04
7.1.01	Truck	0.91738	0.95927	0.90241	-1.88e−03	4.08e−03	-1.90e−04
7.1.02	Airplane	0.94637	0.9467	0.91936	-1.35e−03	2.23e−03	1.04e−03
7.1.03	Tank	0.92665	0.94073	0.90446	-2.69e−03	-3.46e−03	-2.49e−03
7.1.04	Car and APCs	0.96614	0.97538	0.95392	-1.17e−03	6.70e−04	1.46e−03
7.1.05	Truck and APCs	0.90661	0.93685	0.88725	-4.51e−03	1.12e−03	-8.10e−04
7.1.06	Truck and APCs	0.90045	0.93465	0.88065	-3.92e−03	6.38e−04	3.34e−04
7.1.07	Tank	0.86813	0.8768	0.82074	-3.03e−03	-2.04e−04	-1.32e−03
7.1.08	APC	0.92423	0.95333	0.91346	-1.88e−03	3.75e−03	2.08e−04
7.1.09	Tank	0.92675	0.96239	0.91523	-3.11e−03	1.84e−03	-2.76e−03
7.1.10	Car and APCs	0.94504	0.96181	0.92815	-2.16e−04	-3.24e−03	7.66e−04
Boat.512	Fishing boat	0.96993	0.93638	0.92308	5.46e−04	-3.22e−03	1.83e−04
Elaine.512	Girl (elaine)	0.9697	0.97256	0.96796	-1.19e−03	5.92e−04	-1.12e−03
House	House	0.95059	0.97305	0.93846	4.29e−03	-8.68e−04	-2.47e−03
Gray21.512	21-level step wedge	0.99984	0.99653	0.99636	1.55e−03	-1.49e−03	8.19e−04
Numbers.512	256-level test pattern	0.71603	0.73889	0.64186	1.32e−03	-3.03e−05	1.43e−03
	Azafack	0.95872	0.94002	0.92429	1.94e−04	3.10e−03	-5.24e−04
	Guefack	0.99057	0.99022	0.98472	1.60e−03	5.02e−04	6.64e−04