Table 4 PSNRs of watermarked images using the maximum of 
of each block.
of each block.From: Digital Watermarking Method Warranting the Lower Limit of Image Quality of Watermarked Images
| Â | MTF | JPEG75 | JPEG50 |
|---|---|---|---|
aerial | 30.0 | 34.4 | 32.8 |
airplane | 28.6 | 35.1 | 34.9 |
balloon | 37.6 | 40.1 | 38.7 |
couple | 33.5 | 40.0 | 38.3 |
earth | 34.9 | 40.2 | 38.1 |
girl | 32.8 | 38.1 | 37.2 |
lena | 30.1 | 38.2 | 36.3 |
mandrill | 25.0 | 33.4 | 31.5 |
milkdrop | 34.9 | 37.7 | 36.5 |
parrots | 29.5 | 40.4 | 37.1 |
pepper | 29.9 | 34.1 | 31.8 |
sailboat | 32.6 | 35.9 | 35.2 |