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

Table 5

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

Image name	Correlation coefficients of original images			Correlation coefficients of cipher images
	Vert. cor	Hor. cor	Diag. cor	Vert. cor	Hor. cor	Diag. cor
ANTAMOEBACOLI	0.77141	0.81532	0.67636	−2.96e−03	1.31e−03	1.06e−05
Article_oeuf_taeniaC2	0.93107	0.9308	0.87861	−1.94e−03	−5.14e−03	7.55e−04
Balantidium coli cyst	0.76953	0.78613	0.66231	1.74e−03	−6.15e−04	6.42e−04
Balantidium coli_trophozoite	0.9259	0.93259	0.90567	2.19e−03	−3.48e−03	1.56e−04
DICROCOELIUM	0.97729	0.98048	0.96751	3.89e−04	3.14e−03	−5.42e−04
Entamoeba coli trophozoite	0.99129	0.99215	0.98588	−1.85e−03	−9.26e−04	3.17e−03
Entamoeba histolytica cyst	0.93725	0.94537	0.90185	2.47e−03	−2.75e−03	−2.22e−03
Entamoeba histolytica-cyst-Gini	0.92637	0.91525	0.85601	1.69e−03	−2.96e−03	−2.11e−04
Entamoeba histolytica trophozoite	0.98471	0.98541	0.97413	2.36e−03	2.87e−03	9.35e−04
Entamoeba histolytica trophozoite_redim	0.98253	0.98307	0.96996	−1.73e−03	−2.91e−03	−3.19e−04
Entamoeba histolytica trophozoite_redim2	0.98622	0.9867	0.97545	2.20e−03	1.51e−04	−8.70e−05
oeuf_ascarisc	0.93155	0.93445	0.88098	2.59e−04	−1.48e−03	−6.88e−04
S-Hematobium egg	0.88554	0.92383	0.8354	−1.64e−03	−2.70e−03	−1.60e−03
S-Mansoni egg	0.86917	0.9053	0.80198	−3.42e−03	4.26e−04	1.10e−03
Tropho_entamoeba_histolytica2	0.99265	0.99139	0.98605	3.29e−03	5.36e−05	1.42e−03
Tropho_iodamoeba_butschlii	0.9966	0.99688	0.99391	−4.73e−04	5.99e−04	−1.66e−03
Angio	0.89905	0.96795	0.90462	−1.78e−03	3.27e−03	−8.62e−04
DisLocElbow	0.96446	0.99666	0.9608	1.40e−03	5.22e−04	1.54e−03
Echo1	0.88904	0.8776	0.8212	1.77e−03	−2.03e−04	3.88e−04
I1_200	0.99393	0.98775	0.98353	7.66e−04	8.84e−04	1.20e−03
Node2	0.96491	0.95401	0.93398	3.21e−03	2.26e−03	−9.21e−04
Ossify	0.99017	0.94411	0.9303	2.44e−03	2.14e−03	9.73e−04
Pelvis	0.94299	0.99754	0.93903	−1.73e−03	1.78e−03	−3.68e−03
Ribs	0.87322	0.88588	0.85227	−2.05e−04	−8.69e−04	1.70e−04
Dirofilaria	0.98814	0.97363	0.96349	−9.60e−04	−8.31e−04	−4.47e−04
Headirm	0.96343	0.95734	0.93986	−2.08e−03	6.53e−04	1.32e−03
Abdomenirm	0.91929	0.91331	0.8508	−1.35e−03	−6.20e−05	3.75e−04
Pelvisirm	0.96602	0.95567	0.93225	−9.36e−04	4.49e−04	2.93e−04
Gastrointestinal_parasites	0.91404	0.94614	0.88418	−3.06e−04	−2.40e−03	5.55e−05
Echo fetus at 12 weeks	0.91943	0.90556	0.85116	7.24e−04	−3.15e−03	−1.24e−03
Ultrasound of fetus of 3 months	0.96781	0.98601	0.95989	−1.85e−03	−1.60e−03	2.34e−03
Echopelv	0.89428	0.90612	0.82813	−9.96e−04	−1.11e−03	3.76e−04
CT-MONO2-8-abdo	0.93917	0.95915	0.91275	−2.57e−03	−3.56e−03	−2.56e−04
OT-MONO2-8-colon	0.96189	0.96556	0.93819	−2.33e−03	5.95e−04	−4.25e−04