Table 1.
Adjacent pixel correlation analysis test for different test images.
| Correlation Coefficient Directions | |||||||
|---|---|---|---|---|---|---|---|
| Plain Image Directions | Ciphered Image Directions | ||||||
| Image | Size | HD | DD | VD | HD | DD | VD |
| Splash | 512 × 512 | 0.9839 | 0.9773 | 0.9913 | 0.0011 | 0.0037 | 0.0029 |
| Pepper | 512 × 512 | 0.9768 | 0.9639 | 0.9792 | −0.0009 | 0.0033 | 0.0008 |
| Tiffany | 512 × 512 | 0.9381 | 0.8943 | 0.9409 | 0.0002 | −0.0006 | 0.0057 |
| Airplane | 512 × 512 | 0.9663 | 0.9370 | 0.9641 | 0.0006 | −0.0011 | 0.0029 |
| Baboon | 512 × 512 | 0.8665 | 0.7262 | 0.7587 | −0.0038 | 0.0003 | 0.0007 |
| Fruit | 512 × 512 | 0.9738 | 0.9552 | 0.9743 | 0.0020 | 0.0022 | 0.0041 |
HD = Horizontal pixels direction, DD = Diagonal pixels direction, VD = Vertical pixels direction.