Table 4.
Correlation coefficients of the proposed scheme.
| Test Image | Color Channel | Direction | Plain Image | Cipher Image | Cipher Image Obtained by [10] |
|---|---|---|---|---|---|
| Lena | R channel | Horizontal | 0.980042 | −0.006439 | 0.009238 |
| Vertical | 0.989399 | −0.001656 | 0.001778 | ||
| Diagonal | 0.969445 | 0.007549 | 0.004084 | ||
| G channel | Horizontal | 0.968884 | −0.002014 | 0.0062322 | |
| Vertical | 0.982293 | 0.000549 | 0.0076567 | ||
| Diagonal | 0.955277 | 0.001466 | 0.0053490 | ||
| B channel | Horizontal | 0.933162 | 0.000000 | 0.0073123 | |
| Vertical | 0.958172 | −0.001465 | 0.0067766 | ||
| Diagonal | 0.918504 | −0.001098 | −0.0051781 | ||
| House | R channel | Horizontal | 0.954274 | −0.000549 | 0.004812 |
| Vertical | 0.953098 | 0.000916 | 0.000535 | ||
| Diagonal | 0.918540 | −0.004959 | 0.001604 | ||
| G channel | Horizontal | 0.933637 | −0.006428 | 0.012478 | |
| Vertical | 0.927962 | 0.001653 | 0.006774 | ||
| Diagonal | 0.871893 | 0.000917 | 0.006414 | ||
| B channel | Horizontal | 0.975040 | −0.002933 | 0.011060 | |
| Vertical | 0.959132 | −0.002566 | 0.007135 | ||
| Diagonal | 0.938001 | −0.001280 | −0.001784 | ||
| Peppers | R channel | Horizontal | 0.958355 | 0.003853 | 0.005328 |
| Vertical | 0.964731 | 0.001284 | 0.004085 | ||
| Diagonal | 0.949474 | −0.001832 | 0.006211 | ||
| G channel | Horizontal | 0.977986 | −0.000912 | 0.008552 | |
| Vertical | 0.977363 | 0.001460 | 0.009086 | ||
| Diagonal | 0.961298 | 0.002366 | 0.000178 | ||
| B channel | Horizontal | 0.964817 | −0.001647 | 0.008550 | |
| Vertical | 0.960795 | 0.006770 | 0.009263 | ||
| Diagonal | 0.940662 | −0.000366 | −0.000534 | ||
| Average absolute value | 0.002405 | 0.005851 | |||