Table 3.
Performance comparison of NC an PSNR values comparison between proposed and existing scheme
| PSNR (db) | NC | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Proposed Scheme (Two Grayscale watermarks insertion of 32 × 32 size) | Zairi et al. [37] | Takore et al. [31] | BW & Permana [34] | Thanki et al. [33] | Hsu et al [15] | Goli & Naghsh [13] | Ernawan et al. [8] | Awasthi et al. [3] | Proposed Scheme (Two Grayscale watermarks insertion of 32 × 32 size) | Zairi et al. [37] | Thanki et al. [33] |
| 56.76161 | 46.959 | 44.5866 | 47.7949 | 47.18 | 40.49 | 38.37 | 47.176 | 50.4728459 | 0.999798 | 1 | 0.9827 |
| 56.92657 | 44.42 | 44.5218 | 47.4966 | 46.54 | 40.48 | 39.93 | 46.918 | 48.9276355 | 0.999813 | 1 | 0.9647 |
| 57.27539 | 32.66 | 44.5866 | 48.5741 | 46.55 | 40.16 | 38.74 | 46.116 | 49.7361311 | 0.999892 | 1 | 0.9780 |
| 57.06924 | – | – | – | – | 40.46 | 39.6 | 47.024 | 49.7085744 | 0.999445 | – | – |
| 56.82357 | – | – | – | – | – | – | 47.158 | 52.0171729 | 0.999681 | – | – |
| 56.98985 | – | – | – | – | – | – | 47.300 | 50.3163369 | 0.999485 | – | – |
| 56.95649 | – | – | – | – | – | – | 47.404 | 50.811477 | 0.999441 | – | – |
| 57.27628 | – | – | – | – | – | – | 47.352 | 49.9880453 | 0.999396 | – | – |
| 57.15844 | – | – | – | – | – | – | 47.365 | – | 0.999623 | – | – |
| 56.92342 | – | – | – | – | – | – | 47.311 | – | 0.999734 | – | – |