Table 5 Sample watermark images, attack type and their respective extracted watermark.
From: Enhanced medical image watermarking using hybrid DWT-HMD-SVD and Arnold scrambling
Attack type | Watermarked image | Extracted watermark |
|---|---|---|
No Attack |
|
|
PSNR = 49.86 | NC = 1.00 | |
JPEG2000 compression |
|
|
PSNR = 48.50 | NC = 0.98 | |
Sharpening attack |
|
|
PSNR = 47.00 | NC = 1.00 | |
Gaussian low-pass filter |
|
|
PSNR = 46.83 | NC = 1.00 | |
Average filter |
|
|
PSNR = 46.78 | NC = 1.00 | |
Median |
|
|
PSNR = 45.58 | NC = 1.00 | |
JPEG compression |
|
|
PSNR = 44.20 | NC = 1.00 | |
Salt and pepper noise |
|
|
PSNR = 35.69 | NC = 0.99 | |
Speckle noise |
|
|
PSNR = 34.18 | NC = 0.96 |
